biology practical manual for form four

Transcription

RWANDA EDUCATION BOARD (REB)
P.O. BOX 3817 KIGALI
www.reb.rw
BIOLOGY
A PRACTICAL MANUAL
Kigali, January 2015
1
Biology Practical Manual for S.4
SENIOR 4
© 2015 Rwanda Education Board
All rights reserved:
This practical manual is the property of REB and credit must be provided to author and source
of the document when the content is quoted.
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Preface
During this period when most developing countries are strongly advocating for technology
and modernization, emphasis is being put on the teaching of science in all schools as one
way of achieving economic and social development. This technology and modernization
advancement can be realized by practicing science in its real sense. For the better way of
teaching and learning science, we don’t have to neglect the crucial role of experiments in
school science curriculum.
In regard to vision 2020, Rwanda projects to have adequate, highly skilled scientists and
technicians to satisfy the needs of the national economy. There is a need to generate,
disseminate and acquire scientific skills as well as technological innovations, in addition to
integrating them into the social and economic development drive. In order for Rwanda to
achieve this objective, it will have to develop the teaching of science and technology at
primary, secondary and university levels.
The purpose of this manual is to provide a repertoire of practical investigations and home
work questions suitable for advanced level biology students. The manual is self contained
and can be used independently. It is designed to be user friendly and in line with the
current biology curriculum. It is a suitable tool for a candidate to do biology practical paper.
This manual is designed to cover all senior four practical lessons. It is composed of the
following chapters: classification of living organisms, plant kingdom, kingdom fungi,
kingdom protoctista, kingdom monera and animal kingdom.
Each chapter starts by back ground information followed by various activities. Each activity
has a specific objective, an introduction, a rationale, requirements, procedure, and
interpretation of expected results or conclusion. The time for each activity is proposed.
Each experiment was performed for feasibility and proved right. It ends up with the
references at the back of the manual and the glossary of some scientific words used in the
manual. It is hoped that this manual will be of help, to biology teachers as well as students in
guiding them on how different experiments can be carried out during the course of study.
I wish to sincerely extend my appreciation to the people who contributed towards the
development of this document, particularly REB staff and teachers who organized the whole
process from its inception. Any comments and contribution would be welcome for
improvement of this practical manual.
Dr. John Rutayisire
Director General, Rwanda Education Board
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Acknowledgements
I wish to sincerely extend my special appreciation to the people who contributed towards
the development of this manuscript. It would not have been successful without the
participation of different education stakeholders from different schools that I would like to
express my deep gratitude.
My thanks first go to the Rwanda Education Board staffs who were involved in the
conception and writing of this practical manual. I wish to extend my appreciation to
teachers from different schools whose efforts during conception were much valuable.
We also acknowledge the textbook approval committee who approved this manuscript to be
used in schools.
Dr. Joyce Musabe,
Head of department,
Curriculum and Pedagogical Material Production Department
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The list of participants who were involved in the elaboration of the practical manual
1.
Rwanda Education Board Staff
Mr. Rutakamize Joseph, Director of Science Unit/CPMD
Mr. Rugengamanzi N. Felecian, Curriculum Specialist, Biology /CPMD
Mr. Muhaya Anaclet, Examiner, Biology, Rwanda Education Board
2. Teachers
Mr. Nkwasibwe Benson, Gashora Girls’ Academy
Mr. Matenda M. Gustave, Kagarama Secondary School
Mr. Hezron L. Joseph, Lycèe De Kigali
Mr. Mujuni Patrick, Fawe Girls’ School
3. Text book approval committee (TAC) members
Dr Musabe Joyce, Member and Chairperson
Mr. Gasana Janvier, Member
Mr. Rutakamize Joseph, Non Permanent Member
Mr. Gakwerere François, UR Collage of Education, Non Permanent Member
Mr. Rugengamanzi Nkubana Felecian, Curriculum Specialist, Biology (Non Permanent
Member)
Mr. Nshimiyimana Alexis, Secretary TAC
4. Desktop publisher
Mr. Ntambara Jean, CPMD
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Preface……………… ..............................................................................................................................................3
Acknowledgements ...........................................................................................................................................4
Note to users ........................................................................................................................................................9
How to use this practical manual.............................................................................................................. 11
Biology laboratory safety rules.................................................................................................................. 12
Tips for biological drawings ....................................................................................................................... 13
Commonly used biology laboratory equipments ............................................................................... 14
General objectives........................................................................................................................................... 15
Chapter 1: Classification and diversity of living things ...................................................... 16
Background information.................................................................................................................... 16
Activity 1: Identification of external features of living organisms (50 minutes) ...................... 17
Activity 2: Construction of a dichotomous key (100 minutes) .................................................. 20
Activity 3: Identification of different organisms in the five kingdoms (100 minutes) .............. 28
Activity 4: Classification of the animal groups by taxonomic hierarchy (50 minutes). ............ 35
Activity 5: Classification of plant groups by taxonomic hierarchy (50 minutes) ...................... 39
Chapter 2: The plant kingdom ..................................................................................................... 44
Activity 1: Comparison between flowering and non flowering plants (50 minutes collection
time excluded). ........................................................................................................................... 45
Activity 2: Comparison between external structure of monocotyledonous and dicotyledonous
plants (50 minutes)..................................................................................................................... 49
Activity 3: Identification of different leaf modifications (50 minutes) ..................................... 53
Activity 4: Observation of flower parts (50 minutes) ................................................................ 57
Activity 5: Identification of inflorescence (50 minutes) ............................................................ 61
Activity 6: Dissection of a drupe (25 minutes) .......................................................................... 65
Activity 7: Dissection of a berry (20 minutes)........................................................................... 68
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Activity 8: Observation of types of placentation (50 minutes) .................................................. 72
Activity 9: Dissection of a typical seed and a maize grain (25 minutes) ................................... 74
Activity 10: Mechanisms of fruit and seed dispersal (50 minutes) ........................................... 78
Activity 11: Experiments to show the conditions necessary for germination (set the experiment
for a week) ................................................................................................................................. 80
Activity 12: Stages and types of germination (a week) ............................................................. 84
Activity 13: Demonstration of asexual reproduction in plants by cuttings (2 weeks) ............... 87
Activity 14: Demonstration of asexual reproduction in plants by fragmentation (3 weeks) ..... 89
Chapter 3: Fungi kingdom ............................................................................................................. 93
Activity 1: Observation of black mould on bread, Rhizopus sp (50 minutes) ........................... 93
Activity 2: Comparison between bread mould and Penicillium sp (30 minutes) ...................... 96
Activity 3: Observation of gill structure of a mushroom (20 minutes)...................................... 99
Chapter 4: Kingdom protoctista ............................................................................................... 101
Background information.................................................................................................................. 101
Activity 1: Microscopic observation of named protists (Paramecium, Amoeba, Euglena, and
Unicellular algae) (100 minutes) ............................................................................................. 101
Activity 2: Microscopic observation of permanent slides of protoctists (50 minutes) ............ 105
Chapter 5: Prokaryote kingdom/ Monera ............................................................................ 108
Activity 1: Microscopic observation of bacteria (30 minutes) ................................................ 108
Activity 2: Classification of bacteria (50 minutes) .................................................................. 111
Chapter 6: Animal kingdom ....................................................................................................... 114
Activity 1: Identification of main animal phyla (50 minutes) ................................................. 114
Activity 2: Classification of arthropods into classes (100 minutes) ........................................ 120
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Activity 3: Identification of a typical insect (20 minutes) ....................................................... 127
Activity 4: Observation of mouth parts of insects (50 minutes) .............................................. 130
Activity 5: Observation of insects’ wings and hind limbs (50 minutes).................................. 135
Activity 6: Differentiation of vertebrate groups (50 minutes) ................................................. 139
Activity 7: Field trip to a national park, zoos or any convenient local sites (6-8 hours) ......... 144
Distribution of practical experiments per term................................................................. 146
Term 1: Experiments .................................................................................................................................. 146
Glossary……………………………………………………………………………………………………………...148
Bibliography ................................................................................................................................... 153
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Note to users
This book is intended to be used by students, teachers as well as the laboratory technicians.
Dear students;
When using this book, you are requested to do the following:
Read the general objectives of this book as mentioned below before conducting any activity.
Read the theory related to each activity before conducting suggested activities.
Follow the instructions related to the activity to be conducted. Some materials should be
collected or prepared in advance.
Apply the safety rules while conducting an experiment in the laboratory.
Always have your dissection kit and put on a laboratory coat while conducting an
experiment.
Ask for clarification from the teacher where you do not understand.
Conduct the experiment and write down your findings before comparing them to the
suggested answers in this book.
Dear teachers;
When using this practical manual you are recommended to:
Read in advance the content of the activity to be conducted before taking students in the
laboratory.
Remember to collect and prepare in advance the required materials and if possible adjust
the list according to what is available in the school environment.
Facilitate students to carry the activities alone and therefore emphasize on their skills
(manipulation, observation, analytical, interpretation and presentation).
Experiments involving the use of micro-organisms, and other body fluids, or where students
act as subjects, are potentially hazardous. They should be carried out under close
supervision.
In the case of dissection and use of live animals, some people object on ethical grounds to
experiments on live animals and physiological preparations. The various examination
boards have policies, and teachers are advised to familiarize themselves with the current
guidelines.
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Dear laboratory attendant/ laboratory technician;
You need to be involved in the activity that the biology subject teacher has planned to
conduct with students. Therefore, read the procedures in advance (or may be required to
have your own copy of manual guide) and then prepare the required material. You may
suggest to the teacher alternatives in order to achieve the same objective of the activity.
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How to use this practical manual
The manual contains six chapters studied in S4. The chapters are distributed in three terms
and only two chapters are covered each term. Each chapter is structured in such way that it
begins with brief background information, the theory related to the chapter. The teachers,
students and technicians are advice to read the background information before they begin
the activity that follows. Each activity begins with the objective and has introduction,
significance in real life situation, materials that will be necessary to conduct the activity and
this is followed by a procedure on how to carry out the task.
In most chapters where necessary the manual reviles the interpretation of the results as
well as probing questions and proposed responses at the end of each chapter to both the
teacher and the student. This serves as a guide to other activities not provided in this
manual. It will guide the teacher to plan his lessons and even those activities not set out in
this manual.
Students are to follow the steps provided by the manual for each activity up to the end. The
manual is a user friendly and can be used independently or in groups under the teacher
instructions and should be taught together with the theory lessons.
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Biology laboratory safety rules
Biology laboratory safety rules are guidelines designed to help keep you safe when
experimenting. Some equipment and chemicals in a biology laboratory can cause serious
harm. Most biology laboratories have the safety rules posted in the laboratory and your
instructor will most likely go over them with you before you begin working. It is always
wise to follow all laboratory safety rules.
Do not forget, the most helpful safety rule is to use plain old common sense.
The following laboratory safety rules are a sample of the most basic rules that should be
followed when you are in biology laboratory:
Be prepared for the experiment you are going to conduct.
When working, make sure you keep your area neat and organized. If you happen to spill
some chemicals on your table try to clean them before they dry.
Be careful, you may be working with glass or sharp objects, so you don't want to handle
them carelessly.
Wear protective clothing when you are conducting an experiment. Each student must
have a laboratory coat (apron).
Be cautious with chemicals, if any chemical comes in contact with your skin, wash
immediately with water and inform your laboratory instructor. Wear protective eyewear
when handling chemicals.
Be sure you know where to find all safety equipment in the biology laboratory. This
includes such items as the fire extinguisher, first aid kit, broken glass receptacles, and
chemical waste containers. Also be sure you know where all the emergency exits are
located and which exit route to take in case of an emergency.
Do not eat or drink in the laboratory.
Do not taste any chemicals or substances you are working with.
Do not use your mouth for pipetting substances.
Do not handle broken glass with bare hands.
Do not pour chemicals down the drain without permission.
Do not operate laboratory equipment without permission.
Do not perform your own experiments unless given permission.
Do not leave any heated materials unattended.
Do not place flammable substances near heat.
Do not engage in childish antics such as horseplay or pranks.
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Tips for biological drawings
Diagrams representing biological structures should be drawn with the following in
consideration:

They must be large enough, neatly drawn in a sharp pencil and correctly labeled in
ink.

The label lines should not criss-cross each other and should not have arrow heads.
Use horizontal label lines which touch the intended part.

Draw the correct section or view asked for. The section may be transverse or
longitudinal. The view may be anterior (ventral), side or posterior (dorsal).

When drawing cross-section, use double continuous outline. Never use a ruler or
compass to draw biological structures. A ruler should be used to draw horizontal
label line.
The following are selected examples of areas one needs to note while drawing biological
structures:
(i) Cross-section of a fruit e.g. Orange.

Seeds should be shown in at least one loculus.

Double outline representing the epicarps should be shown.
(ii) Cross-section of a flower.
Note the positioning of the ovary (inferior or superior) in respect to whether other floral
parts arise.
Note the number of stamens and stigmas.
The following are suggested diagrams one should be familiar with in sinior four: members
of phylum arthropoda and chordate and major division of kingdom plantae,

Bread mould (rhizopus).

Wind and insect pollinated flowers.

Structure of fruits and seeds.

Seedlings showing epigeal and hypogeal germination.

Finned fish showing external features.
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Commonly used biology laboratory equipments
Microscope
Sweepnet
Pasteur dropper
Test tube rack
Test tube holder
Dissection kit
Petri dishes
Hand lens
Beaker
Dissecting board
Specimen bottles
Test tubes
Dissecting dish
Inoculation loop
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General objectives
At the end of senior four, learners should be able to:
Apply general principles of classification to explain diversity of living organisms.
Explain and relate structures of living organisms to their functions and ecological habitat.
Differentiate living organisms in their environment basing on their morphological features.
Acquire basic practical as well as methodological knowledge concerning natural facts.
These principal scientific qualities are: capacity to observe phenomena objectively, critical
attitudes in observations, capacity to analyze and comprehend biological facts, critical
thinking and problem solving, critical analysis and biological interpretation of facts,
commitment to work and the will to communicate research findings.
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Chapter 1: Classification and diversity of living things
Background information
Biologists have identified and named about 1.5 million species so far. They estimate that
anywhere between 2 and 100 million additional species have yet to be discovered. Thus, a
system or a way of classifying them has continued to be at the fore front of taxonomists to
classify organisms. They organize them into groups that have biological significance. The
science and practice of classification is called taxonomy.
Organisms are classified into kingdoms, phyla, classes, orders, families, genera and species.
This system is called taxonomic hierarchy. As one moves down the hierarchy, the range of
organisms in each group narrows while similarities increase.
A species is a population of organisms that share similar characteristics and can breed with
one another and produce fertile offspring.
The scientific name of an organism is composed of a name from its genus and species for
example, Homo sapiens. This naming is referred to as binomial system.
When identifying organisms, keys are applied, especially the dichotomous keys, where the
organisms are split into successive pairs based on clearly seen characteristics.
Factors considered when classifying organisms include external features, cell structure and
chemical constitution.
The old system of dividing living organisms into plant and animal kingdoms had been
replaced by the five kingdom system. Viruses are on the grey area between living and non
living things.
The kingdom monera consists of prokaryotic organisms.
The kingdom protista contains all unicellular eukaryotes, though with some multicellular
eukaryotes.
Kingdom fungi contain eukaryotic saprotrophs and parasites that have economic
importance.
Kingdom plantae consists of photosynthetic multicellular eukaryotes.
Kingdom animalia contains multicellular eukaryotes that are generally motile and feed by
heterotrophic
Natural classification of organisms is based on the external features rather than genetic or
cellular structures.
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Activity 1: Identification of external features of living organisms (50 minutes)
Specific objective
Differentiate living organisms using their external features.
Introduction
External feature can be referred to as an exterior or surface of an organism, which relates to
its physical appearance.
When one observes the external features of living organisms, he/she comes out with
distinctive characteristics that allow to identify specimen and to differentiate it from each
other. For example, a fly is different from snail which has a wing and no shell.
Rationale
Organisms are diverse in nature. Human beings interact with various organisms which are
socially and economically important in our lives. Thus, there is need to understand a wide
range of living organisms.
Requirements
Sweep nets
Specimen bottles
Hand lens
Forceps
Petri dishes
Preserved specimens
Insecticides
Formaldehyde
Surgical blades
Cotton wool
Pins
Microscope
Permanent slides
Charts
Precaution
1)
Some organisms are poisonous, some have thorns and others are able to sting.
Care must be taken during the time of collection.
2)
Collection of specimen should be done a day or few days before the experiment
due to the difficulty one may face in getting all of them at once.
Procedure
i)
Using sets of appropriate materials collect a variety of specimen of organisms.
Suggested organisms: grasshoppers, bean plant, maize plant, cockroach, bees,
butterflies, millipede, black jack, frog, gecko, moss, fern, and mushroom. Unicellular
organisms may be provided as prepared slides of amoeba, paramecium,
plasmodium, bread mould (rhizopus) and bacteria of milk (lactobacillus)
ii)
Observe collected specimens in the laboratory.
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iii)
Identify specimens and split them into main groups according to their differences
and similarities.
iv) Tabulate the features and differences between the groups in form of a table like
the one below:
Table 1: Features, example and economic importance for each group of specimen
Specimen groups
Group A:
Group B:
Group C:
Group D:
Group E:
Features
Examples of
organisms
Economic
importance
v) Preserve specimens for future use.
Discussion questions
1.
2.
3.
4.
5.
How many groups can you identify?
Name the identified groups.
State at least two examples of organisms from each of the groups.
State one unique feature for organisms in each of the groups.
In each group, identify a single organism and state its economic importance to
man if any.
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Suggested answers to discussion questions
Table 2: Summary of the results of the discussion questions
Features
Examples
of
organisms
Specimen groups
Group a:
Group b:
Animalia
Plantae
Locomotory They are
structures,
green, some
distinct eyes have body
and mouth.
with distinct
parts: roots,
stem and
leaves
Grasshopper Bean plant,
cockroach,
maize plant,
bees,
black jack,
butterflies,
moss and
millipede,
fern.
frog, gecko,
Economic
Bees
importance Provide
honey,
pollinators
Bean plant
provide
food, add
nutrients to
the soil
Group c:
Fungi
Non green,
no roots,
leaves and
stems.
Group d:
Protoctista
They are
microscopic and
unicellular
Group e:
Monera
Lack of a
defined
nucleus.
Mushroom,
Amoeba,
paramecium,
plasmodium.
Lactobacillus
Rhizopus.
Mushroom
provides
food,
mineral
nutrients
and fibers.
Amoeba
Lactobacillus
Some species
fermentation
cause diseases
of milk
of the
alimentary canal
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Activity 2: Construction of a dichotomous key (100 minutes)
Specific objective
Construct a dichotomous key and use it to classify the provided specimens.
Introduction
One tool used to identify unfamiliar organisms is a dichotomous key. A dichotomous key is
a series of paired statements that describe physical characteristics of different organisms.
In this activity you will use dichotomous key to identify specimens provided such as leaves,
roots, seeds, stems, flowers, arthropods etc.
Rationale
Organisms vary in their external features. These features determine the extent to which
they can adapt to their external environment and their survival.
Requirements
Sweep nets
Specimen bottles
Hand lens
Forceps
Petri dishes
Surgical blades
Cotton wool
Pins
Roots
Stems
Leaves
Insecticides
Formaldehyde
Flowers
Seeds
Arthropods
Precaution
1) Some organisms are poisonous, some have thorns and others are able to sting.
Care must be taken while handling them.
2) Collection of specimen should be done a day or few days before the experiment.
Procedure
A. Use of leaves
In this activity you will use dichotomous key to identify provided leaves using the
following features: whether a leaf is simple or compound, leaflet arrangement, leaf and
leaflet shapes, venation, texture, appearance of the leaf edge etc
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i.
ii.
Collect leaves of different species for both simple and compound (cassava,
avocado, jacaranda, cassia; hibiscus, bean, maize).
Label different leaves collected as, A, B, C, D, E, F and G respectively.
C
B
A
E
D
F
G
Figure 1(A-F): Types of leaves collected from different plants
iii.
iv.
v.
Observe and familiarize with the specimens before starting the experiment to
minimize errors during the identification process
Use sharply contrasting external features of collected leaves and start grouping
them into two successive groups until each leaf is identified as illustrated by an
example that follows:
Preserve the specimen for future use.
Note that colour is not a dichotomous characteristic but black and non-black are
dichotomous characteristics.
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1a) Simple leaves (B, E A and G)…………………………………go to 2
b) Compound leaves (A, C, D and F)…………………..………go to 4
2 a) Parallel venation…………………………………………….........G
b) Leaves with network venation………………………...........go to 3
3 a) Leaves with smooth margin………………………………….B
b) Leaves without serrated margin……………………………E
4 a) Trifoliate leaves ………………………….……………………….F
b) Non trifoliate leaves……………………………………………..go to 5
5 a) Digitate leaves……………………………………………………...A
b) Non digitate leaves………………….…………….........................go to 6
6 a) Pinnate leaves…………………………………….………….............D
b) Bipinnate leaves……………………………………..…………….C
1.)
Which steps have you followed to identify the following?
Specimen
Steps followed
Identity/name
G
…………………..
…………………….
D
………………….
………………………
C
………………….
……………………….
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1.
The steps followed to identify specimen G, D, and C are:
Specimen
Steps followed
Identity/name
G
1.a and 2.a
Maize plant
D
1.b, 4.b, 5.b and 6.a
Cassia
C
1.b, 4.b, 5.b and 6.b
Jacaranda
Note that the dichotomous key can also be done with: roots, stems, flowers or seeds and
fruits.
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B. Use of arthropods
i.Label the following collected specimens of arthropods as: A, B, C, D, E, F and G
respectively. Honey bee, spider, millipede, butterfly, sugar ant, centipede and
mosquito.
ii.Observe and familiarize yourself with the specimens before starting the experiment to
minimize errors during the identification process.
iii.Observe external features to construct a dichotomous key
Figure 2: Dichotomous tree of arthropods
iv.Use sharply contrasting external features of collected specimens and construct a key
while grouping specimens into two successive groups until each specimen is
identified as illustrated by an examples that follow:
1a) with 3 pairs of legs----------------------------------------------------go to 2
b) with more than 3 pairs of legs---------------------------------------go to 5
2a) with wings---------------------------------------------------------------go to 3
b) without wings----------------------------------------------------------E
3a) with pollen sacs---------------------------------------------------------A
b) Without pollen sacs----------------------------------------------------go to 4
4a) with straight antennae-------------------------------------------------G
b) with coiled antennae---------------------------------------------------D
5a) with four pairs of legs---------------------------------------------------B
b) With more than four pairs of legs------------------------------------go to 6
6a) cylindrical body shape--------------------------------------------------C
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b) With flattened body shape----------------------------------------------F
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Which steps are followed to identify the specimen A, B, C, D, E, F and G?
Specimen
Steps followed
Identity/name
A
----------------------
-------------------------
B
----------------------
C
----------------------
-------------------------
D
---------------------
------------------------
E
---------------------
-------------------------
F
---------------------
------------------------
G
--------------------
------------------------
-------------------------
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The steps followed to identify specimen A, B, C, D, E, F, and G are:
Specimen
Steps followed
Identity/name
A
1a, 2a, and 3a
Honey bee
B
1b and 5a
Spider
C
1b, 5b and 6a
Millipede
D
1a, 2a, 3b and 4a
Mosquito
E
1a and 2b
Sugar ant
F
1b, 5b and 6b
Centipede
G
1a, 2a, 3b and 4b
Butterfly
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Activity 3: Identification of different organisms in the five kingdoms (100 minutes)
Specific objective
Examine the representatives of organisms in each kingdom.
Introduction
A kingdom is the largest grouping in the taxonomic categories of classification. The
biologist looks for what he/she regards as important features shared by as large a group as
possible. For example it is easy to find out that most animals move freely, are heterotrophs
and lack cell walls, whereas plants have chlorophyll. In other cases, it becomes hard to
separate plants from fungi and bacteria, since all have a cell wall.
Rationale
The largest groups of organisms known so far are kingdoms. The reason for putting
organisms into these large groups is to sort them out into manageable groups seen to have
main features in common. It is in this method of grouping that we can establish how
organisms could have changed over time giving rise to different but related new organisms.
Requirements
Prepared slides or charts of eubacteria
Cyanobacteria
Euglena
Trypanosome
Amoeba
Paramecium
Plasmodium and spirogyra
Specimens or charts of mucor
Agaricus (mushroom)
Green algae
Liverworts and mosses
Ferns
Pinus
Cypress
Bean plant
Bees
Snails
Earth worms
House flies
Lizard
Rabbit,
Tilapia,
Hen
Frog
Light microscope.
Hand lens.
Note that:
For permanent slides’ use, prior examination should be done by the teacher to check
their viability and availability.
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For paramecium and amoeba, culturing should be done a day or two days in advance.
Charts and microphotographs may be used in case the permanent slides are not
available.
Field survey around the school to collect some specimen.
Procedure
Step 1: Observation of monera
Under a microscope, examine the prepared slides of eubacteria and cyanobacteria.
Draw each observed specimen.
What do they have in common?
Step 2: Observation of protoctista
Under a microscope, examine the prepared slides of euglena, trypanosomes,
amoeba, paramecium sp and plasmodium sp.
What are the main distinguishing features of observed slides?
Step 3: Observation of fungi
Under a microscope, examine a mucor (pin mould) and write down your
observation.
By using a hand lens, observe the R. agaricus (mushroom) and write down your
observation.
What do they have in common?
Step 4: Observation of plants
Examine the following specimens using a hand lens where necessary: green algae,
liverworts, mosses, ferns, cypress or pinus and bean plant.
From your own observation, state the distinguishing features of the observed
specimen.
Step 5: Observation of animals
Observe the following specimens: bees, snails, earth worms, house flies, lizard,
rabbit, tilapia, hen and a frog.
From your own observation, state the distinguishing features of the observed
specimens.
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Representation of each the mentioned kingdom
Chain of cyanobacteria or blue-green algae (A monera)
Bacterium (A monera)
Amoeba (A protoctista)
Mucor (fungus)
Agaricus (fungus)
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Green algae
liverwort
Moss
Fern
Cypress
Pinus
Bean plant
Bee
31
Snail
Tilapia (fish)
Earthworm
Lizard
Rabbit
Hen
Frog
Figure 3: Example of species representing kingdoms
32
Use the information collected above from step 1 up to step 5, fill the table below:
Table 3: Characteristic features of kingdoms
Kingdom
1.
Monera
2.
Protoctista
3.
Fungi
4.
Plantae
5.
Animalia
General features
33
Observed specimen /
slides
The following table shows the five kingdoms, their features and gives some examples for
each kingdom.
Table 4: Characteristic features of the 5 kingdoms
Kingdom
General features
1.
Monera
-
2.
Protoctista
-
3.
Fungi
-
4.
Plantae
-
5.
Animalia
-
Unicellular
Undifferentiated
nucleus
Unicellular
Differentiated
nucleus
Lack chlorophyll
Fixed on substrate
Undifferentiated
body
Green color
Fixed on substrate
Don’t show
locomotion
Distinct body parts
No chlorophyll
Specific mode of
locomotion
34
Observed specimen /
slides
Eubacteria and
Cyanobacteria.
Euglena, Trypanosomes,
Amoeba, Paramecium and
Plasmodium.
Mucor, R.agaricus
(mushroom)
Green algae, Liverworts,
Mosses, Ferns, Cypress or
Pinus and Bean plant.
Bees, Snails, Earth Worms,
Houseflies, Lizard, Rabbit,
Tilapia, Hen and a Frog.
Activity 4: Classification of the animal groups by taxonomic hierarchy (50 minutes).
Specific objective
Differentiate animals and put them into different groups using their external features.
Introduction
Organisms are grouped together into sets, creating a hierarchy. Species are grouped into
genera, genera are grouped together into families, families into orders, orders into classes,
classes into phyla (animals) or divisions (plants), and phyla or divisions into kingdoms.
Rationale
To study biology of organism requires wide knowledge on the structures of that particular
organism. With that knowledge, man can manipulate the environment around him for his
benefit.
Requirements
Sweep nets
Petri dishes
Specimen bottles
Preserved specimens
Pins
Surgical blades
Microscope
Cotton wool
Permanent slides
Labels
Charts
Models
Hand lens
Insecticides
Forceps
Formaldehyde
Precaution
Some organisms are poisonous, some have spines, spikes and others are able to sting. Care
must be taken while handling them. Also care should be taken, not to inhale fumes of
reagents being in use, while collecting the specimens.
Procedure
i.Collect cockroaches and snails that represent their respective phyla from an identified
environment using appropriate apparatus.
ii. Label the specimens to be identified.
iii.Observe and familiarize yourself with the specimens before starting the experiment to
minimize errors.
iv.Classify the named organisms in different phyla using contrasting characters that suit
them.
35
v. Preserve some specimen for future use.
1.
Use of human model and charts as an example
Workings in groups identify characteristics of man that place him in phylum chordata.
These include:
Presence of notochord/ vertebral column.
Segmented muscle blocks.
Pharyngeal clefts.
Circulation in which blood flows forward ventrally and backwards dorsally.
The naming of man by taxonomical hierarchy is as follow:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primate
Family: Hominidae
Genus: Homo
Species: Homo sapiens
2.
Use of cockroach
The students shall as well work in groups to identify characteristics of cockroach that place
it in phylum arthropoda. These characteristics l include:
Chitinous cuticle.
Jointed appendages.
Presence of exoskeleton.
Presence of cuticle which undergoes moulting.
Presence of compound eyes.
Figure 4: Cockroach
36
The naming of cockroach by binomial system is as follow:
Kingdom: Animalia
Phylum: Arthoropoda
Class: Insecta
Order: Dictyoptera
Family: Blattidae
Genus: Blatta
Species:Blatta orientalis
3.
Use of snail ( Garden snail)
Finally under the guidance of the teacher, the students shall identify characteristics of
garden snail and place it in its respective phylum. These characteristics include:
Presence of soft muscular foot on the ventral side of the body.
Presence of visceral hump on the dorsal side that contains digestive system and
protected by the hump.
Presence of the rasping tongue–like radula for feeding.
Presence of gills for breathing.
They have trochophore larva during their development stage.
Figure 5: Garden snail
The naming of snail by binomial system is as follow:
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Pulmonata
Family: Helicidae
Genus: Helix
Species: Helix aspersa
1.
2.
State the kingdom to which man, cockroach and snail belong?
What happens as one descends down the taxonomic hierarchy?
37
1. They all belong to the kingdom animalia.
2. As one descends the hierarchy, organisms tend to differ greatly in their features. Hence
in different divisions, classes, orders, families, genera and species.
38
Activity 5: Classification of plant groups by taxonomic hierarchy (50 minutes)
Specific objective
Differentiate plant species and put them into different groups using their external features.
Introduction
Plants are grouped together into sets, creating a hierarchy. Genera are grouped together
into families, families into orders, orders into classes, classes into phyla/divisions and
divisions into kingdoms.
Rationale
The study of plants requires wide knowledge on their structures. With that knowledge,
man can use them for his benefit and for the environment management.
Requirements
Pins
Microscope
Permanent slides
Charts
Hand lens
Forceps
Petri dishes
Preserved specimens
Surgical blades
Soil auger/ uprooting implement
Labels
Iodine/phloroglucinol
Flowered bean and maize plants
Precaution
Some plants are poisonous, some have spines, thorns and others are able to sting. Care must
be taken while handling them.
Procedure
i. Collect bean plant, maize plant and fern that represent their respective phyla from an
identified environment using appropriate apparatus.
ii. Label the specimens collected.
iii. Observe and familiarize yourself with the specimens before starting the experiment to
minimize errors.
iv.
Classify the named plants in different classes or sub classes using contrasting
characters that suit them.
39
v.
Preserve some specimen for future use if necessary.
Note that bean plants, maize plants and fern belong to the same division tracheophyta but
different classes. Thus, their classification differs from the class level in the hierarchy. Their
common features include:
Their life cycle shows alternation of generations where the sporophyte is dominant.
Sporophyte differentiates into roots, stem and leaves with vascular tissues.
They all have lignified tissues.
1.
Use of bean plant
From the above information, work in groups to identify characteristics that place bean
plant in class angiospermae and sub-class dicotyledon. These include:
Presence of flowers.
The ovules are protected by the ovary.
Leaves have network of veins.
Stems have a ring of vascular bundles.
Presence of two cotyledons.
Presence of two leaves during germination.
Figure 6: Bean plant
The naming of bean plant by hierarchy is as shown below:
Kingdom: Plantae
Phylum: Tracheophyta
Class: Angiospermae
Sub-Class: Dicotyledons
Order: Fabales
Family: Fabaceae (formerly Leguminosae)
Genus: Phaseolus
Species: Phaseolus vulgaris
40
2.
Use of maize plant
Identify the characteristics that place the maize in its sub-class monocotyledon, and shall
involve the embryo with one seed leaf and leaves with parallel venation.
Figure 7: Maize plant
The naming of maize plant by binomial system is as follow:
Kingdom: Plantae
Phylum: Tracheophyta
Class: Angiospermae
Sub-Class: Monocotyledonae
Order: Poales
Family: Poaceae (formerly Graminnae)
Genus: Zea
Species: Zea mays
3.
Use of fern
Learners shall finally classify fern into its class, in the hierarchy basing on the following
characteristics: presence of sporangia on leaves (fronds) and posses’ underground stem
(rhizome).
41
Figure 8: Fern
The naming of fern by taxonomical hierarchy shall involve the following:
Kingdom: Plantae
Phylum: Pteridophyta
Class: Psilotopsida
Order: Ophioglossales
Family:Ophioglossaceae
Genus: Thelyteris
Species: Thelyteris totta
1.
2.
State the kingdom to which bean, maize and fern belong?
What happens as one descends down the taxonomic hierarchy?
42
1.
2.
They belong to the same kingdom plantae.
As one descends the hierarchy, organisms tend to differ greatly in their features.
Hence in different phyla / divisions, classes, orders, families, genera and species.
43
Chapter 2: The plant kingdom
Kingdom plantae comprises about 260,000 known species including flowering and nonflowering plants. The plant kingdom contains multicellular eukaryotes which are usually
sedentary and feed by photosynthesis. These are algae, bryophytes, pteridophytes,
gymnosperms and angiosperms.
Only a tiny percentage of plant species are directly used by humans for food, shelter, fiber
and drugs including rice, wheat, corn, legumes, cotton, conifers, etc on which whole
economies and nations depend.
The presence of flowers, the ability to produce fruits, the type of leaf venation, and the
number of cotyledons in seeds are criteria based on to classify plants.
All plants have a general organization which includes vegetative and reproductive organs.
With reference to a typical flowering plant such as avocado tree, the vegetative organs
include: roots, stem and leaves while reproductive organs are flowers which can produce
fruits containing seeds.
Many plants reproduce by sexual and asexual modes. The life cycle has two distinct phases
- the diploid sporophyte and haploid gametophyte – that alternate with each other. This
phenomenon is called alternation of generation.
44
Activity 1: Comparison between flowering and non flowering plants (50 minutes
collection time excluded).
Specific objective
Differentiate flowering from non flowering plants basing on external features.
Introduction
One of the simplest approaches of classifying plants based on their external features is
splitting them into flowering and non flowering plants.
Flowering plants also called phanerogams, produce flowers and in addition, they have
roots, stem and leave as vegetative organs. E.g. beans, cassava, cypress, maize. Non
flowering plants also called cryptogams do not produce flowers. Some classes have no
root and no conductive tissues e.g. algae and moss.
Rationale
From the earlier stages in plant growth, one cannot differentiate flowering from non
flowering plants. As they get mature and reproduce external features appear distinctive.
We need to know these distinctive features in order to group plants into flowering and non
flowering for a better exploitation of the biodiversity in our environment.
Requirements
Plant specimens
Hand lens
Forceps
Petri dishes
Ferns
Maize plant
Bean plants
Lichens
Gloves
Preserved specimens
Surgical
Green algae
Surgical blades
Cotton wool
Pins
Microscopes
Slides
Chart
Methanal,
45
Procedure
i. Collect the following specimens of plants: filamentous green algae from the swamps, a
mature fern, oxalis plant, mature bean plant, mature moss, and mature maize plant. What
do they have in common?
ii. Label collected specimens A, B, C, D, E, and F respectively.
iii. Observe their differences and group them into flowering and non flowering plants.
Filamentous
Green algae (a)
Bean plant (d)
Mature fern (b)
Moss plant (e)
Oxalis plant (c)
Maize plant (f)
Figure 9: Specimens of flowering and non flowering plants (a-f)
Interpretation of the results
All the specimens collected are green due to the presence of chlorophyll. They all are
multicellular eukaryotic and autotrophic.
The ability to produce flowers makes these plants to be divided into flowering plants for
example oxalis, bean and maize and non flowering plants for example green alga, fern and
moss.
It follows that plants which produce flowers fit in the sub-division of phanerogams while
non flowering plants fit in the sub-division of cryptogams therefore these two groups
cannot be differentiated on the basis of the height or appearance at early stage but only on
the basis of the ability to produce flowers.
46
1. What is the easier way of confirming whether a plant is phanerogam or cryptogam?
2. Can you conclude from the seedling whether a plant is a phanerogam or a cryptogam?
Why?
3. Can you confirm from the size (height) of a plant whether it is a phanerogam or a
cryptogam? State an example from the observed list.
47
1. Specimens A, B, and E are non flowering plants while plants C, D and F are flowering
plants.
2. External features of seedling cannot allow concluding whether a plant is non flowering
or flowering plant because at the young stages flowers are not formed yet.
3. The height of a plant does not allow concluding whether a plant is phanerogam or
cryptogam. For example the fern is taller than oxalis and yet it is a cryptogam while the
latter is a phanerogam.
48
Activity 2: Comparison between external structure of monocotyledonous and
dicotyledonous plants (50 minutes)
Specific objective
Differentiate monocotyledonous from dicotyledonous plants basing on external features.
Introduction
The angiosperms are divided into two major groups that are given the status of classes;
dicotyledons and monocotyledons. These two classes of angiosperms differ from each
other by the structure of their roots, stems, leaves and seeds.
Rationale
Many plants are more important, economically, than others that is why we need to know
their distinctive features in order to group these plants into monocotyledonous and
dicotyledonous for a better exploitation of the biodiversity in the environment.
Requirements
Avocado plant
Hand lens
Surgical blades
Maize plant
Bean plants
Plant specimens
Sorghum plant
Gloves
Preserved specimens
Soaked seeds of maize, sorghum, beans
Procedure
i.Collect roots, leaves and seeds from each of the following specimens: maize plant, bean
plant, avocado and sorghum.
ii. Label the collected specimens A, B, C, and D.
Bean root (b)
Maize root (a)
49
Avocado root (c)
Sorghum root (d)
Figure 10: Different collection of roots (A-D)
iii.Observe and compare the morphology of roots of collected plants. Is there any
difference?
iv.With reference to the root morphology split all the collected specimens into two main
groups. What is the distinctive feature?
v.Observe the venation systems on the leaves of all collected specimens. Is there any
difference?
vi.With reference to the leaf venation system, divide collected specimens into two main
groups.
vii.Carry out the longitudinal dissection of the seeds from each specimen to observe the
number of cotyledons in each.
viii. With reference to the number of cotyledon per seed, divide the collected specimens
into two main groups. Is there any difference?
Interpretation of results and conclusion
Some plants have adventitious morphology (maize and sorghum) while others have tap
root system (avocado and bean).
Maize and sorghum leaves have parallel venation while bean and avocado have
network like venation (reticulate venation).
Maize and sorghum have a single cotyledon per seed while avocado and bean have two
cotyledons.
Maize and sorghum have similar features i.e. Have adventitious roots, parallel venation on
their leaves and a single cotyledon per seed. These are external characteristic of plants
under the class of monocotyledonous plants.
50
On the other hand, avocado and bean have similar features i.e. tap root system, reticulate or
network venation on their leaves and the presence of two cotyledons per seed. These
plants fall the class of dicotyledonous plants.
1.
Observe the couch grass (urwiri) leaves and predict whether it is a
monocotyledonous or a dicotyledonous plant. Give reason.
2.
State and compare any four examples of monocotyledonous plants and other
four examples of dicotyledonous plants.
51
The couch grass is a monocotyledonous plant because it has parallel venation on its leaves.
Table5: Examples of monocotyledonous and dicotyledonous plants
Monocotyledonous plants
Dicotyledonous plants
Bamboo, wheat, rice, sugar cane, star grass, Soya bean, eucalyptus, hibiscus, pea bean,
spear grass, etc
orange, etc
52
Activity 3: Identification of different leaf modifications (50 minutes)
Specific objective
Identify types of leaf modifications and to explain their usefulness.
Introduction
Leaves are generally green bladelike organs on which the photosynthesis takes place.
However, for their adaptation to the environmental changes, the leaf can modify its
external morphology.
Rationale
Some plants are adapted on the arid regions and develop mechanism of reducing the rate of
water loss. There is a need of knowing different modifications on the leaves for the plant
adaptation and therefore to predict the habitat of a given plant specimen.
Requirements
Scissors
Hand lens
Gloves
Dissecting dish
Surgical blades
Tendrils of passion fruit
Cactus piece of stem
Euphorbia leaves
Cucumber and datura
Preserved specimen, charts
Precaution/ safety
Some leaves have thorns or poisonous hairs which can cause allergies.
Procedure
i.
ii.
iii.
Collect the leaves of the following specimens: tendrils of passion fruit, cactus piece of
stem, euphorbia leaves, cucumber, datura and avocado.
Label these leaves A, B, C, D, E and F respectively. Why do you label them?
Observe the external features and note down modifications if any. Suggest reasons of
the observed modifications.
53
Tendrils of passion fruit (a)
Cucumber leaves (d)
cactus stem (b)
datura leaves (e)
euphorbia leaves (c)
avocado leaves (f)
Figure 11: Different collection of leaves (A-F)
Tendrils of passion fruit are modified leaves which allow the plant to roll round for
support.
Hairs on the cucumber leaves and thorn on the lamina of datura leaves are mainly
adaptation for defense mechanism.
The leaves of the cactus are reduced into thorn to reduce the surface area for the water
loss.
It follows that most of the plants in arid regions have reduced surface area in form of
thorns or scales to reduce the water loss by transpiration.
Only avocado leaf does not have modification. Euphorbia has reduced leaves, cucumber leaf
has hairs, datura has thorns on its lamina while cactus has leaves reduced in thorns. The
tendrils of the passion fruit are threadlike leaves.
54
Note to the teacher:
Specimens to be collected and studied will depend on the availability of the plants. Make
sure that specimens to be collected by learners are not poisonous.
1. The leaves of some plants of arid regions are fleshy (thick). Suggest an advantage of
such a leaf modification.
2. Some aquatic plants have a large surface area and many stomata on the upper side.
Discuss the advantages of these modifications.
3. Explain aquatic plants do not survive on dry land those of dry land do not survive in
water.
55
Suggested answers to the discussion questions
1. Fleshy leaves contain abundant water to supply to plant need during the dry season.
2. The large surface area and numerous stomata on the upper side offer the advantage of
losing excess water up taken.
3. Aquatic plant cannot survive on dry land because of its numerous stomata from it loses
too much water than it absorbs. Terrestrial plant cannot survive in water because of
lack of adaptation to loss extra water.
56
Activity 4: Observation of flower parts (50 minutes)
Specific objective
Observe and draw the structures of a flower and identify which structures become the seed
and fruit.
Introduction
Flowers are reproductive organs that are composed of four kinds of specialized leaves:
sepals, petals, stamens and carpels. Sepals are in many plants green and resemble ordinary
leaves whereas petals are often brightly colored and found just inside the sepals. Stamen is
a male part of the flower and produces male gametes called the pollen grains .The male
reproductive parts are collectively called Androecium. Each stamen consists of a filament, a
thin stalk that bears an anther .carpals or pistil –is the female part of the flower. The female
reproductive parts are collectively called Gynoecium it consists of one or more units called
carpels. A carpel consists of an ovary, a style above the ovary and one or more stigmas.
Requirements
Flower
Forceps
Scalpel
Microscope slide
Razor blade
Dropper pipette
Cover slips
Microscope
Procedure
i.Collect a flower specimen (e.g. Hibiscus)
ii.Examine that flower carefully. Note whether the anthers are above or below the stigma.
iii.Using a razor blade, dissect, draw and label a longitudinal section of the flower.
iv. Remove an anther head and put it on a slide. While holding the anther with forceps, use
the scalpel to cut one or more thin slices of the anther head.
v. Place the slices flat on microscope slide and add a drop of water and a cover slip. Observe
the slides with the microscope using low power. Make a labeled drawing of your
observations.
vi. Prepare a fine and longitudinal section of the ovary then mount it on slides to observe on
microscope. Draw and label your observation.
57
Presentation of the results
Self pollinated flowers typically have anthers higher than the stigma, and pollen falls
directly from the anthers onto the stigma. Many cross-pollinated plants have taller stigmas
that receive wind ground or animal-born pollen from other flowers
The anther head contains the pollen grains.
The ovary contains ovules.
( a)
( b)
(c)
(d)
Figure 12: Flower (a), longitudinal (b, c) of a flower and transverse section of anther head
(d).
58
In many flowers, both sepals and petals are brightly colored and help attract pollinators. In
other plants, the sepals’ function is to protect the more fragile flower bud from damage.
Different flower parts develop and produce seeds and fruit formation.
Pollen grains form male gametophyte that can fertilize female gametophyte and form
zygote that will grow into new plants.
The ovules produce female gametophytes that can be fertilized by male gametophytes.
The ovules will become the seeds. Generally, the ovary becomes the fruits, although other
parts of the flower may also contribute to fruit formation.
The flower diagram inserted in this manual is not exactly that of a hibiscus but we have
used it to allow the learner to familiarize with the part of a flower.
1. Describe the reproductive organs of hibiscus flower.
2. Write the floral formula and draw the floral diagram the of a hibiscus flower
59
1. Hibiscus flower has the following features:
It is basically bisexual represented as
5 sepals which are fused, represented as K (5),
5 petals which are free, represented as C5,
Stamens are numerous and filaments of stamens are fused, represented as (∞),
5 carpels, fused and ovary is superior, represented as G (5).
2. The floral formula of hibiscus is:
K(5) C5 A(∞) G(5) and its floral diagram is as follows:
Figure 13: Floral diagram of hibiscus (Hibiscus rosa-sinensis)
60
Activity 5: Identification of inflorescence (50 minutes)
Specific objective
Differentiate between the arrangements of flowers on a plant.
Introduction
Flowers on a plant can be isolated or grouped. The arrangement of flowers on a plant
varies from a species to another.
Flowers can alternate on their peduncle, they may achieve the same height, they can
develop from the same node, etc.
Rationale
Inflorescences of groups of flowers are often used to embellish or decorate rooms and
public places. The wonders of flowers are their arrangements, their colors and their scents.
We humans need to know different arrangements of flowers on plants that are in our
environment.
Requirements
Scalpels
Dissection dish
Variety of flowering plants some with
single flowers and others displaying
different inflorescences
The specimens to be collected will
include: hibiscus, bluebell, plantain, oat,
elder, cherry, parsley, buttercup and
dandelion.
61
Procedure
Figure 14: Types of inflorescence
i. Collect different types of flowers (attached to the stalk) including: hibiscus, bluebell,
plantain, oat, elder, cherry, parsley, buttercup and sunflower or any flowers with or
without inflorescence.
ii. Label them A, B, C, D, E, F, G, H and I, respectively.
iii. Observe each specimen and identify its type. Which ones do not group in set? How is
called the set of flowers on the same stalk?
Collected flowers are grouped; some have inflorescences except hibiscus.
There different types of inflorescences. These include:
Racemes (Bluebell)
Spike (Plantain)
Panicle (Oat)
Corymbs (Elder)
Simple umbel (Cherry)
Compound umbel (Parsley)
Cyme (Buttercup)
Capitulum (Sunflower)
62
Inflorescence is a particular arrangement of flowers on a single main stalk of a plant. There
are many different types of inflorescence which are classified into two main groups
depending on whether the tip of the flower axis goes on producing new flower buds during
growth ( e.g. Raceme) or loses this ability (e.g. Cyme)
Some inflorescences are simple while others are compound.
Discussion question
1. What should consider in classifying types of inflorescence?
2. Collect onion inflorescence and state its type.
Some of the suggested inflorescence may not be found near your school or you might not
know some suggested specimen. You have to replace the unavailable and unknown
specimens by other of the same type.
63
Suggested answers to discussion question
When classifying inflorescence, we refer to the position of flower, their arrangement on the
stalk and the ability of the stalk to produce further floral buds.
Onion flowers are grouped in simple umbel.
64
Activity 6: Dissection of a drupe (25 minutes)
Specific objective
Describe the structure of a drupe.
Introduction
A fruit is a structure formed from the ovary of a flower, usually after the ovules have been
fertilized.
It consists of the fruit wall (pericarp) enclosing the seed. Other part of the flower, such as
the receptacle, may develop and contribute to the structure, resulting in a false fruit.
The fruit may retain the seeds and be dispersed as whole (an indehiscence of fruit), or it
may open to release the seeds (a dehiscent fruit).
Fruits are divided into two main groups depending on the whether the ovary wall remains
dry or become fleshy (succulent). Succulent fruits are generally dispersed by animals and
dry fruits by wind, water, or by some mechanical means.
Rationale
Edible fruits are preferred according to their structure, sizes and the composition. These
criteria can be visible when you carry out the dissection of a fruit and be able to study them
well. One can be able to differentiate them visually and be able to predict their importance
in the daily life.
Requirements
Scalpel
Hand lens
Transparent ruler
Avocado fruit
Mango fruit.
Procedure
i. Make a longitudinal section of an avocado fruit and mango fruit
ii. Observe main layers from the outside to the inner most of the fruit.
iii. Draw and label different parts of an avocado fruit.
iv. From the diagram drawn, determine the magnification.
65
An avocado fruit has three main layers. The outer layer is skin-like wall which covers the
fleshy like part in the middle. The seed is covered by a brown thin layer. The seed is made
up of two cotyledons.
Figure 15: Cross section of a drupe
Interpretation of result and conclusion
An avocado fruit as well as the mango fruit are in the category of drupe fruits.
A drupe is a fleshy fruit that develops from either one or more several fused carpels and
contains one or many seeds. It consists of the following layers: the epicarp (outer), the
mesocarp (middle) and the endocarp which encloses the seed.
The three parts of the fruit (epicarp, mesocarp and endocarp) make up the pericarp of a
fruit. The pericarp develops from the ovary wall of the flower.
1)
State any other two examples of fruits which have drupe structure such as that of
an avocado or a mango.
2)
Explain the relationship between parts of a fruit and those of a flower.
3)
Which part from an avocado fruit is edible? Why?
Note to the teacher
The drupe diagram suggested above is a generalized structure not neither that of an
avocado nor that of a mango fruit. But the labeling used in this diagram can be used to label
main parts of any drupe containing a single seed.
66
Other examples of drupes: coconut, palm nut
The stalk of the fruit is the derivate to the flower peduncle, the pericarp is the derivate of
the wall of the flower ovary, and the seed is derivate of the fertilized seed.
The mesocarp is the edible part of an avocado fruit. This part contains nutrients (lipids,
proteins, starch and vitamins) and in addition, it is soft for digestion.
67
Activity 7: Dissection of a berry (20 minutes)
Objective:
Describe the structure of a berry.
Introduction
A berry is fleshy fruit formed from either one carpel or several fused together and
containing many seeds.
The fruit wall may have two or three layers but the inner layer is never hard and stony (as
in some drupes).
A berry has general a soft epicarp such as that of tomatoes but a berry which develops a
hard epicarp such as that of a cucumber is called pepo.
Rationale
Egg fruits, tomatoes and citrus fruits are among fruits included in our diet and essential for
our health. These fruits have structure which differs from that of a drupe.
Requirements
Scalpel
Hand lens
Orange fruit
Egg fruit
Charts
Procedure
68
Figure 16: Longitudinal and transversal of a tomato
i.Make a longitudinal or transversal section of a tomato fruit
ii.Observe main layers from the outside to the innermost of the fruit.
iii.Draw, label different parts of a tomato fruit and indicate the magnification.
The tomato fruit develops from the ovary of the flower. The tomato is fleshy due to the
pericarp walls and skin. Finally there are several seeds in each tomato. Tomatoes can be
either bilocular or multilocular. Most cultivated varieties except cherry tomatoes have four
or five locules. The locules are surrounded by the pericarp. The pericarp includes the inner
wall, columella; the radial wall, septa; and the outer wall. The pericarp and the placenta
comprise the fleshy tissue of the tomato.
69
The tomato though commonly classified as a vegetable is really a fruit, a berry in fact.
Tomato fruits exhibit all the common characteristics of berries. The berry is the most
common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp.
They may have one or more carpals with a thin covering and fleshy interiors. The seeds are
usually embedded in the flesh of the ovary. A plant that bears berries is said to be
bacciferous. Many species of plants produce fruit that are similar to berries but not actually
berries and these are said to be baccate.
1. Which part of the tomato flower develops into fruit?
2. Label the following figure
Figure 17: Transverse section of a tomato
3. Explain why tomato fruit is a berry.
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Tomato fruit develops from the wall of its flower ovary.
Figure 18: Labeled structure of a tomato
Tomato is a fleshy fruit in which the entire ovary wall ripens into an edible pericarp.
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Activity 8: Observation of types of placentation (50 minutes)
Specific objective:
Observe and locate the different types of placentation.
Introduction
Placentation refers to the arrangements of seeds in fruit or the arrangements of the ovules
in the ovary. It shows the position of the placenta in a fruit. Seeds are attached to the
placenta by funicle.
Rationale
The seeds are wide components of our diets. The structures of seeds differ from one type to
another but all have similarities that we can observe when we carry out a dissection
Requirements
Scarpel
Hand lens
Bean pod/pea pod
Passion fruit/ pawpaw
Green pepper
Oranges / lemons or tomatoes
Procedure
Collect the following fruits: bean pod / pea pod, unripe passion fruit / pawpaw, green
pepper, oranges / lemons or tomatoes, apple, hibiscus, sunflower.
Part A
i.
ii.
Make a longitudinal section of a bean pod /pea pod carefully along the suture (line of
weakness) to expose the seeds.
Observe, draw and label to show the arrangement of the seeds on the placenta.
Part B
i.
Make a transversal section of unripe passion fruit / pawpaw, green pepper, oranges /
lemons or tomatoes.
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ii.
Observe, draw and label to show the arrangement of the seeds on the placenta
Presentation of results
For the bean pod /pea pod, seeds are attached in a row to the placenta along the ovary wall,
thus marginal placentation.
For the unripe passion fruit / pawpaw, seeds are attached to the placenta on the periphery
of the fruit wall. The placenta is located where carpels fuse thus parietal placentation.
For the green pepper, seeds are attached to the placenta on the base of the ovary thus
basal placentation.
For the oranges / lemons or tomatoes, seeds are attached to a centrally located placenta
thus axile placentation.
Figure 19: Types of placentation
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Activity 9: Dissection of a typical seed and a maize grain (25 minutes)
Objective
Describe and compare the structure of a bean seed and that of a maize grain.
Introduction
The ovules after fertilization develop into seeds. A seed is made up of a seed coat and an
embryo.
The embryo is made up of a radical, plumule an embryonal axis and one (as in wheat,
maize) or two cotyledons (as in beans and pea).
Rationale
The seeds are wide components of our diets. The structures of seeds differ from one type to
another but all have similarities that we can observe when we carry out a dissection.
Requirements
Petri dish
Scalpel
Hand lenses
Soaked bean seeds
Maize grains
Procedure
i. Soak five bean seeds in a Petri dish containing water and leave them for at least 3 to 4
days.
ii. Repeat the same procedure for five maize grains. Why do we soak these seeds and
grain in water several hours before the experiment?
iii.Carry out a longitudinal section of each specimen and note down your observations.
iv. Carry out a transversal section on each specimen and write down your observation.
v. Draw and label the parts of a bean seed and those of a maize grain.
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Figure 20: Internal structures of bean and maize
Both bean seed and maize grain have seed coat, embryo made of plumule and radicle
and cotyledons.
The seed coat of the bean has two layers: the outer testa and the inner tegmen.
Bean seed has two fleshy cotyledons while the maize grain is made of a single
cotyledon.
A seed which has one seed-leaf is described as monocotyledonous, and one which has two,
as dicotyledonous. Maize is monocotyledonous seed while bean is a dicotyledonous seed.
Within the seed coat is the embryo, consisting of an embryonal axis and cotyledons. At the
two end of the embryonal axis are present the radicle and the plumule. The hilum is a scar
on the seed coat through which the developing seeds were attached to the fruit.
In the seed of monocotyledonous seeds of cereals (grains) such as the maize, the seed coat
is membranous and fused with the fruit wall. The outer covering of endosperm separates
the embryo by a protein layer called aleurone layer.
The plumule and radicle of maize grain are enclosed in sheaths which are called coleoptiles
and coleorhizae respectively.
1)
What is the function of each of the following part of a seed:
a) Seed coat
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b) Plumule
c) Radicle
2)
Identify parts labeled k to q from the diagrams below:
Figure 21: Internal structures of bean and maize
A chart can be used to complete the labels and the diagrams.
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The function of:
Seed coat: to protect the cotyledon and embryo
Plumule: to develop into leaves of the young plant
Radicle: to develop the root system of the young plant.
K: seed coat
L: aleurone
M: coleoptile
N: cotyledon
O: plumule
P: radicle
Q: seed coat
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Activity 10: Mechanisms of fruit and seed dispersal (50 minutes)
Specific objective
Describe main mechanisms of seeds dispersal and state agents of seeds dispersal.
Introduction
When flowering is over and the seeds are mature the whole ovary, or the individual seeds,
fall from the parent plant to the ground, where if conditions are suitable germination will
subsequently take place.
In many plants, fruits and seeds are adapted in such a way that they are distributed away
from the parent plant; this helps to reduce overcrowding among plants and competition
for air, water and mineral salts, and results in the colonization of new areas.
The dispersal of fruits and seeds can be done by wind, animals or by self-dispersal.
Rationale
Some species of plants are adapted to some environments where they develop and
progressively spread to achieve a wide surface area. The study of the mechanism of fruit
and seed dispersal is economically important since it can allow us to apply strategies to
promote the dispersal of useful species and to prevent that of harmful species.
Requirements
Eucalyptus fruits
Dry bean legumes
Jacaranda
Mature black-jack plant (bidens pilosa)
Dismodium
Tomato
Mango
Guava
School garden
Charts
Procedure
i. You are provided with the following specimens of fruits: eucalyptus fruits, dry bean
legumes, jacaranda, mature black-jack plant (bidens), dismodium, tomato and cotton.
ii. Observe each of the above specimens and identify the mechanism of dispersal of each.
iii. Give reasons for each suggested mechanism.
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Table 6: Dispersal mechanism
Specimen
Dispersal mechanism
Reasons
Cotton
Mango
Black jack (bidens pilosa)
Guava
Eucalyptus fruit
Dismodium
Tomato
Bean legume
Jacaranda
The mechanisms of dispersal of the suggested specimens are as follow:
Jacaranda, cotton, and eucalyptus: by wind
Mango, tomato by water
Guava by birds
Black jack, tomato by animals
Bean legume by self dispersal
Note for the teacher:
Other specimens can be used if the suggested ones are not available in your area. A field
trip can be organized to observe the dispersal mechanisms of several specimens.
Experiments are designed by collection of different seeds, fruits with features matching
adaptations and the mechanisms of dispersal.
E.g-fruit with pappus of hairs, ripe fruits (oranges, paw paw), black jack with hooks for
attachment to the animal’s body and self explosion (bean pods).
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Activity 11: Experiments to show the conditions necessary for germination (set the
experiment for a week)
Note: this activity should be conducted concurrently with the next activity (stages of
germination)
Specific objective
Explain conditions required for the seed germination.
Introduction
Seeds will only germinate if certain conditions that is favorable. The most important of
these are a supply of water, a supply of suitable temperature and a supply of oxygen. The
following experiments will show the usefulness of each of the above conditions.
Rationale
The germination is the basic step in the reproduction of flowering plants. If the seeds do
not germinate, we cannot expect crops and the famine outcome can result. We need to
know suitable condition for the process of germination so that we can be able to fight
against such outbreak of hunger in our populations /communities.
Requirements
Cotton wool
Large test tubes
Beakers
Bean seeds
Source of heat
Rubber stoppers
Refrigerator
Water
Oil.
Procedure
i. Have four test tubes that will be labeled a, b, c and d.
Figure 22: Test tube (A-D)
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ii. Place a cotton wool at the bottom of each of the four test tubes and set them up in a
test tube rack.
iii. In test tube a, put several crotalaria seeds in a cotton wool and place the test tube in a
warm place, so that the seeds are provided with the warmth and air, but no water.
iv. In test tube b, place some crotalaria seeds on the cotton wool, then fill the tube with
water which has been freshly boiled and cooled. Cover the surface of the water with a
layer of oil to prevent air dissolving in it. Place the test tube in a warm place, so that
the seeds are provided with warmth and water but no air.
v. In test-tube c, moisten the cotton wool with water and place some crotalaria seeds on
it. Put the test-tube in a warm place so that the seeds are provided with warmth,
water and air.
vi. In test-tube d arrange as for test-tube c, but instead of putting it in a warm place,
place it in a cold place like a refrigerator. The seeds in this tube will be supplied with
water and air, but no warmth.
vii. Observe the seeds every day and note which one germinates. Add water as necessary
to keep the cotton wool in tubes c and d moist.
Among the four test tubes, only the seeds in test-tube 3 have geminated.
Interpretation of the results and conclusion
Dry seeds cannot germinate because their seed coat didn’t rupture and the food reserve in
the cotyledon has not been hydrolyzed.
In the absence of air (oxygen), cells of the embryo lack oxygen to oxidize respiratory
substrates which are source of energy required for germination.
In the coldness, seeds do not germinate because enzymes involved in the germination are
not activated.
It follows that water; oxygen and warmth are required conditions for the seed conditions.
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1) Under which of the following sets of conditions do seeds germinate?
Table 7: Conditions for germination
Set
Temperature
Light
Water
Oxygen
A
300c
Absent
Present
Present
B
300c
Present
Absent
Present
C
00c
Present
Present
Present
D
300c
Present
Present
Absent
2) Explain why water is necessary for seed germination.
3) When a bean seed is sowed at 2 m depth it does not germinate even if the soil is moist.
Explain why.
Note for the teacher:
You can also use another specimen of seed provided that it can germinate in short time (e.g.
Bean, maize grain).
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Germination will occur in condition-set because it provides suitable temperature, water
and oxygen.
Water is imbibed by the seed. Hence the seed coat is softened, and the food reserve is
hydrolyzed.
At 2 m depth, the soil lacks oxygen and therefore the seed cannot germinate.
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Activity 12: Stages and types of germination (a week)
Specific objective
Identify the types and stages of germination.
Introduction
The two types of germination are related to the different sources of nourishment available
to the germinating seed. In hypogeal germination the epicotyls elongates, in epigeal
germination it’s the hypocotyl which elongates. Using of potted seeds in moist soil and take
record of the position of the cotyledon with time. Maize and bean seeds are preferred.
The maize: germination of a maize seed illustrates the typical hypogeal germination. There
is a large food reserve in the cotyledon which is needed by the seedling to grow. During
germination the epicotyls grows faster than other parts so that it assists the plumule to
break through the soil leaving the cotyledon below behind.
Note: the structure called coleoptile that protects the delicate plumule from damage as it
passes through soil.
Rationale
Understanding types of germination help farmers and researchers to know more on how to
prepare land so that they can minimize loss of seeds during planting seasons.
Requirements
Maize and been seeds
Water
Wooden/carton box
Moist soil
Watering can
Trowel
Wooden board
Procedure
i)
Soak in water bean and maize seeds in a clean container for 48 hours to soften the seed
coat and break seed dormancy.
ii) Put soil in wooden or carton box half filled.
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iii) Using a stick make seven holes in two rows which are wide apart. Place soaked bean
seeds in one row and maize seeds in another row. One seed per hole as shown below:
Figure 23: diagram showing rows of maize and bean seed
iv) After the seventh day, use a trowel to scoop out one seed from each row, and examine
them.
v) Repeat the above procedure on the 9th and 11th days respectively. Make the
observations as shown below.
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Figure 24: stages of germination of bean seed.
Figure 25: Representation of hypogeal germination
Note:
The germination duration depends on the time after harvest and the type of the seed.
Bean seeds germinate before maize seeds.
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Activity 13: Demonstration of asexual reproduction in plants by cuttings (2 weeks)
Objective
Prove that asexual reproduction takes place in plants by use of cuttings.
Introduction
A sexual reproduction is the production of offspring from a single organism without the
production of gametes. The offsprings are identical to the parent. The most common form
of asexual reproduction in plants is called vegetative propagation. Use of cuttings is one of
the methods involved in artificial propagation.
Rationale
Use of cuttings is an example of artificial propagation. It is currently applied in agriculture
and horticulture. The process is used commercially thus farmers maximize the production
of yields.
Requirements
Growth medium or moist soil
Sweet potatoes vines
Elephant grass
Sugarcane or cassava stems
Secateurs/sharp knife
Rooting hormone
Procedure
i) Collect clean and healthy stems from cassava, sugarcane or potato plants.
Using a secateurs/sharp knife, cut the stem of either cassava, sugarcane or sweet potato
stems into suitable sizes.
ii) Place them in either suitable medium of growth or apply rooting hormone if available
or plant them in moist soil in the school garden.
iii) Leave the set up for about 13 days, and then observe the development of roots and
leaves at nodes.
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Observation and interpretation of results
Use of cassava stems, sugarcane, sweet potatoes planted in moist soil. After about 13 days,
observe the development of roots and leaves at nodes.
Figure 26: Asexual reproduction by cuttings in sugar cane
88
Activity 14: Demonstration of asexual reproduction in plants by fragmentation (3
weeks)
Specific objective
Prove that asexual reproduction takes place in plants by use of fragmentation.
Introduction
A sexual reproduction is the production of offspring from a single organism without the
production of gametes. The offspring are identical to the parent. The most common form of
asexual reproduction in plants is called vegetative propagation. Use of fragmentation is one
of the methods involved in artificial propagation.
Rationale
Use of fragmentation of algae and understanding its rates of growth in different
environments help students to understand how to avoid excess growth of algae in water
bodies.
Use algae that can be made by cutting threads of spirogyra and transferred to glass beakers
with water. Observe the length of threads over time.
Requirements:
Glass beakers of 500ml
Scalpel
Forceps
Pins
Spatula
Weighing balance
Labels
Artificial fertilizers
Clear river water
Spirogyra (algae)
Procedure
i.
ii.
iii.
Label five beakers of the same size as A, B, C, D and E. Pour water in each beaker. Weigh
several measures of artificial fertilizers of 1 g each.
Transfer 1g of fertilizer to beaker a, then 2g to beaker b, 3g to beaker c, 4g to beaker d
then lastly put 5g of fertilizers to beaker e. Note the concentration of fertilizers is
increasing from A- E.
Using forceps pick spirogyra and put it on a tile. Add several drops of water to avoid
drying. Tease off a piece of spirogyra using a pin. Cut that piece into 5 fragments of the
same length and transfer each piece into the beaker.
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iv.
Stand the beakers in a place where they can receive adequate sunlight for the seven
days. On the next day start to examine the fragments in each beaker every day and
record any observable changes such the increase in size of the spirogyra.
Table 8: Rate of growth in plants
Beaker Rate of
growth
Reason
A
B
C
D
E
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Observation and interpretation of results
Figure 27: Asexual reproduction by fragmentation in spirogyra.
It will be noticed that there is an increase in size of algae. However the increase is not
uniform. The spirogyra in beaker (a) and (e) show the least increase in size. Fastest growth
reflected in size of algae is in beaker (b), (c) and (d). One of the factors that control the rate
of growth is the amount of fertilizers in each beaker.
Draw a table as this shown here and record your observation.
Table 9: Rate of growth in plants
Beaker
Rate of growth Reason
A
Low
The amount on fertilizer was little
B
Medium
The amount of fertilizers was more than that in beaker a
C
High
The amount of fertilizers was very high causing abnormal high
rate of growth
D
Medium
The amount of fertilizers was too much that it altered the
water potential in the beaker to be low. The alga is affect as its
cells loose water to the beaker and end up with inadequate
water.
E
Low
The amount of fertilizers was too much that it altered the
water potential in the beaker to become very low. The algae
are affected as their cells loose too much water to the beaker
and fail to grow.
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It is clearly demonstrated that spirogyra is capable of reproducing asexually by the
fragmentation method. It should also be noted that artificial fertilizers have an effect on the
rate of algae growth. Great care must be taken by farmers to avoid polluting rivers with
excess fertilizers on their farms.
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Chapter 3: Fungi kingdom
The fungi kingdom has over 100,000 species classified according their structure and
methods of reproduction. Their methods of reproduction are unlike those of any other
kingdoms.
Fungi are eukaryotic heterotrophs that have cell walls made of chitin that is a complex
carbohydrate that is also found in external skeleton of insects.
Unlike animals, fungi do not ingest food. They digest food outside their bodies and then
absorb it. Many fungi feed by absorbing nutrients from decaying matter in the soil. Others
live as parasites absorbing nutrients from the bodies of their hosts.
Activity 1: Observation of black mould on bread, Rhizopus sp (50 minutes)
Specific objective
To be able to observe the major structures of molds and explain why mould multiply so
fast.
Introduction
Rhizopus is the name given to a genus of molds which grow on the surface of decaying
meat, bread, fruits, and other organic matter. It grows rapidly and in a few days covers the
surface of its food with a dense white or grey mass of hyphae. The young hyphae branches
repeatedly, to give rise to the mycelium.
Rationale
To help explain the ability of moulds to appear and spoils foods even in clean kitchens or
food stores. Mold fungi spoil foods and a need to perfectly preserve our food. The positive
part fungi are that some species digest wood and dead animals bring about decay and rot in
buildings, an important aspect in mineral recycling.
Requirements
Forceps
Bread mould
Microscope slide
Cover slide
Microscope
Blue methylene
93
Procedure
i. Expose fresh bread to dust and moisture for at least a week in advance.
ii. Transfer the exposed bread to a covered jar and leave it for four days. A dense white
or grey mass of hyphae will appear.
iii. Using a forceps, remove the grey mass area of bread mould.
iv. Gently stick the mass on the glass slide containing a drop of blue methylene.
v. Put on the cover slip and then observe the slide under compound microscope.
1)
Draw and label the observed parts
2)
What do you think is the function of the round structures you have observed?
3)
What do you think is the advantage for a single mass of bread mould to produce
so many of the round structures?
4)
How can your observation help explain the ability of moulds to appear on foods
even in very clean kitchens?
5)
Suggest the economic importance of mould to the environment.
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Figure 28: External structure of Rhizopus nigricans
The tangled filaments are hyphae, including rhizoids, stolons and sporangiophores. The
round structures are sporangia.
Sporangia produce and release spores. The production of such a number of sporangia
increases the number of spores released, thus increasing the chances of moulds
reproduction.
Molds produce large numbers of very tinny spores that are easily spread by wind and
animals. Keeping all spores out of the clean kitchen is practically impossible.
They help in recycling of nutrients by decomposing organic matter, cause decay of food;
fungi parasites infect humans and plants.
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Activity 2: Comparison between bread mould and Penicillium sp (30 minutes)
Specific objective
Observe and compare the structures of mould species.
Introduction
Penicillium is one of the best known genera of imperfect fungi. The term imperfect does not
actually mean that there is anything wrong with these organisms but simply means that the
understanding of their life cycles may not be perfect; researchers have never been able to
observe a sexual phase in their life cycles.
The species Penicillium notatum is a mould that frequently grows on fruit and is a source of
anti biotic penicillin.
Rationale
Moulds spoil foods such as bread and can attack crops, causing serious damage to
agriculture. It is therefore important to control raw materials and finished products like
bread. On the other hand, Penicillium sp is important as it produces antibiotics like
penicillin. A better understanding of their structures is therefore important to help identify
which types are of danger or importance to our lives since they are commonly found in
places like kitchens and food stores where fruits like oranges, lemons are kept, and also
take advantage of the medical application of some of the species.
Requirements
Microscope
Slides and cover slips
Micrographs or charts of penicillium
Bread mould (prepared in advance)
Procedure
i. Mount the Rhizopus of bread mould on the microscope and observe under low power.
ii. Display the micrographs of penicillium alongside the microscope for comparison.
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1)
Make a comparison for the characteristics between Rhizopus and Penicillium
(similarities and differences)
2)
Most fruits form blue green fungi on the surface after ripening as they rot. What
form of fungi is this likely to be? Could you have observed important and famous
fungi in your home without realizing it?
3)
What is the biological importance of Penicillium notatum?
97
Interpretation of the results
(a)
(b)
Figure 29: Diagram showing Penicillium sp (a) and Rhizopus sp (b)
1) Table 10: Comparison between penecillium sp and Rhizopus sp
a)
Similarities
i) They have mycelium
ii) They produce spores
iii) No chlorophyll
iv) No distinct root and stem
v) They all grow on decaying organic matter
b)
Differences
Rhizopus sp /Bread mould
Penecillium sp
i) White grey in colour
i) Bluish green, or yellowish green in
ii)
Sporangiophore
colour
iii) Sporangia
ii) Conidiophores
iii) Conidia
2) The fungi are deuteromycota. Possibly, fruits like oranges that have overstayed after
ripening harden on the pericarp with a covering of blue wish orange –green colour. This
seems to be common in fruits that have stayed for long in stores.
3) Penicillium notatum is used in the production of antibiotic penicillin.
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Activity 3: Observation of gill structure of a mushroom (20 minutes)
Specific objective
Observe the fruiting body, gills lined with basidia in a mushroom.
Introduction
When the right combination of moisture and mineral nutrients occurs, spore producing
fruit bodies push above the ground. You would recognize these fruiting bodies as
mushrooms. Each mushroom grows as a mass of growing hyphae that forms a button or
thick bulge at the soil surface.
Rationale
Mushrooms commonly called “white button” are common foods though some species have
been proved to be poisonous. They have been found to be a good source of protein and
mineral nutrients to man. They are cultivated for sale in groceries hence generating income
to society and the country in general.
Requirements
Fresh mushroom
Microscope and hand lens
White paper
Cup
Microscope
Vanish (for preservation)
Procedure
i.Collect samples of mushrooms.
ii.Identify the fruiting body, hyphae and the mycelium.
iii.Hold the mushroom cap upside down to expose the tinny gills.
iv. Remove a section of the gill and put on the plane paper. Observe a radiating pattern on
the paper. Transfer some of the basidiospores onto a slide and examine them with a
microscope.
1)
2)
Describe the structures of the mushroom you have observed.
What do you think is the cause of the radiating pattern on the piece of paper
where the gills were placed?
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3)
In view of your answer in 2 above, what can you comment about the form of
reproduction in mushrooms?
4)
Suggest the importance of mushrooms as members of club fungi.
Figure 30: Diagram showing structures of mushroom
The button cap that is umbrella-like is the pileus. The folded structures underneath the
pileus are called gills. The stalk that supports the cap is the stipe.
The radiating patterns are caused by basidiospores falling on the paper from the gills.
Reproduction is by the formation of tinny spores called basidiospores that can be blown
by wind since they are light.
They are used as a source of protein and mineral nutrient.
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Chapter 4: Kingdom protoctista
This is a kingdom with diverse group that may include more than 200,000 species. A
protist is any organism that is not a plant, an animal, a fungus or a prokaryote. Protists are
eukaryotes that are not members of the kingdoms; plantae, animalia, or fungi. Although
most protists are unicellular, quite a few are not. Protists actually consists hundreds or
even thousands of cells but are still considered protists because they are similar to other
protists that are truly unicellular. In fact protists are defined less by what they are, and
more by what they are not. Examples of protists include freshwater ciliates, spirogyra.
Activity 1: Microscopic observation of named protists (Paramecium, Amoeba,
Euglena, and Unicellular algae) (100 minutes)
Specific objective
Observe a variety of micro organisms to be able to understand what a protest is.
Introduction
Protists are diverse group of mainly unicellular eukaryotes. Under light microscope, they
are motile animal protists and non motile plant protists vary in shape.
A protist is a eukaryote that is not a member of the plant, animal or fungi kingdoms.
Eukaryotes are likely to have evolved from a symbiosis of large eukaryotes with large cells
that were the first organisms to appear.
Rationale
Plant-like protists produce food by photosynthesis and so form an important component of
food chain in water ecosystem.
Fungi like protists act as recyclers of organic material (they help things rot), others harm
living things, and they cause plant diseases such as mildews blights of grapes and tomatoes.
Animal-like protists ingest or absorb food and so can be parasites and pathogens and can
cause harm to man. Some protists are eaten by tiny organisms which in turn are eaten by
larger organisms studying them would broaden ones knowledge on the ecology and the
vital role of such organisms in nature . It is therefore an important step in the control of
diseases they may cause.
101
Requirements
Hay infusion,
Methyl cellulose
Microscope
Microscope slide
Cover slip
Procedure
i. Prepare a mixed culture of hay infusion that contains various protists by collecting
water from ponds containing plant debris, and leaves for 4 to 5 days in a large beaker
together with some dried grass which has been previously boiled
ii. Collect a sample or a drop from the stirred infusion using a dropper pipette put on a
microscope slide. Add a drop of methyl cellulose and a cover slip. Observe the slide
with a microscope under low and high power.
iii. Draw and label each type of organisms you have observed. Try to recall the structures
within cells to help you to label what you have observed.
iv. Draw a chart listing each type of organism that you have observed and its
characteristics as shown below.
Table 11: Characteristics of observed organisms
Organism
Characteristics
102
1) Paramecium is likely to be dominant, the others are rare. Suggest a possible
explanation for this observation?
2) Which other organisms could you have observed?
3) Describe the mode of locomotion as seen under the microscope.
4) Give three differences between any two protists you have observed.
Figure 31: Structure of paramecium, euglena and amoeba
Note:
Paramecium is likely to be dominant, the others are rarely observed.
High population of amoeba can be obtained by collecting different samples of pond water
or stagnant water by the road sides which is getting dry. However, culturing may not give
the best results for obtaining amoeba rather than other protists.
N.B: The teacher should make sure that the water collected contains the amoeba before the
students start the practical to avoid frustration.
103
Paramecia feed on other small micro-organisms: bacteria, amoeba, and so on. Therefore,
paramecium population appears dominant than other micro-organisms.
Other unicellular organisms observed were: euglena and amoeba.
The observed organisms in motion were paramecia that showed repetitive beating of
cilia, creating “a swimming” current.
The observed differences are summarized in the following table:
Table 12: Comparison between paramecium chlamydomonas and amoeba
Paramecium
Chlamydomonas
Amoeba
- Presence of cilia
- Presence of 2 flagella
- Presence of pseudopodia
- More abundant
- Rare
- Rare
- Present on decaying - Present on decaying - Present on muddy water
organic matter
organic matter
- Regular
swimming - Irregular
floating - Slow sliding movement
movement
movement
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Activity 2: Microscopic observation of permanent slides of protoctists (50 minutes)
Specific objective
Explain external and internal organization of protists.
Introduction
Animal-like protists are heterotrophs and are distinguished from one another by their
means of movements. For example;
- Ciliates that move by means of cilia eg paramecim
- Sarcodines that move by extention of their cytoplasm eg amoeba
- Zooflagellates that swimwith flagella eg, trypanosomes
- Sporozoans do not move on their own at all eg, plasmodium.
- Phytoflagellates have flagella eg chlamydomonas
- Unicellular green algae eg, ulva.
All have the nucleus, cytoplasm and a membrane. The nucleus may vary in number and the
presence of chloroplast in photosynthetic species.
Rationale
Protists are unicellular with varied cell structures. A detailed study of their components
helps find a link between these organisms and their habitat which may include movement
and feeding. For example, the green structures common to some species indicate they are
photosynthetic in nature and so part of food chains. The presence of hair and whip-like
structures suggests aquatic habitat.
Requirements
Microscope
Permanent microscope slides
Charts and photos for detailed structure of protists
Procedure
i. Observe permanent microscope slides of a paramecium, euglena, plasmodium,
multicellular algae, and amoeba under low and high power.
ii. Draw and label each type of organism you have observed.
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1. What are the four major phyla of the animal-like protists? How do members of each
of these groups move?
2. How do the macro and micro nuclei differ in structure?
3. Compare the animal-like protists that have flagella to those that have cilia.
4. How do most unicellular algae get food? How does this differ from the way most
animal-like protists get food?
5. What is the role of unicellular algae in the environment?
6. Algal blooms are a greater danger to fresh water. Identify two ways in which this
problem can be solved.
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1. Zooflagellates, sporozoans, cililata and sarcodina. Zooflagellates and phyto
flagellates move by swimming in helical motion using flagellum. Sporozoa do not
move at all. Ciliates move by use of cilia that beat to and fro in a wave motion.
Sarcodines move by extensions of their cytoplasm.
2. Macro nucleus is bigger in size while micro nucleus is much smaller.
3. A comparison of animal-like protists that have flagella to those that have cilia.
Table 13: Flagellate and ciliate compared
Animal protists with flagella
- examples; trypanosomes,
- have flagella.
- some live within other organisms
Animal protists with cilia.
- paramecium
- have cilia
- most are free living
4. Most unicellular algae use sunlight energy to produce food. Animal-like protists get
food by absorbing, capturing or trapping it.
5. They are at the base of aquatic food chains and they make up considerable part of
the phytoplankton. Unicellular also form symbiotic relationship with other
organisms.
6. Eliminate discharge in water and reduce the amount of plant fertilizers on farms
near water bodies.
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Chapter 5: Prokaryote kingdom/ Monera
Microscopic life covers nearly every square centimeter of earth. There are micro organisms
of many different sizes and shapes even in a single small drop of water. The smallest and
most common micro organisms are called prokaryotes. They are unicellular organisms that
lack the nucleus.
For a very long time, most prokaryotes were called ‘bacteria’. Until fairly recently, all
prokaryotes were placed in a single kingdom called Monera. Prokaryotes are so small and
may seem difficult to tell one type from another. Prokaryotes are identified by
characteristics such as shape, the chemical nature of their cell walls, the way they move,
and feed.
Activity 1: Microscopic observation of bacteria (30 minutes)
Specific objective:
Appreciate that there are bacteria in the air.
Introduction
Bacteria are the smallest organisms having a cellular structure. They are unicellular and so
only seen individually by a microscope and occur almost in every environment. Bacteria
occupy many environments such as soil, air, water, dust, in and on animals and plants and
can even be found in hot springs at temperatures above 600c or higher. Their numbers are
enormous
Rationale
The activities of bacteria are vital to all organisms because they cause decay and recycling
of nutrients in the environment. In addition, they are of great importance to man because
they can be utilized in many economically important processes like medicine, industry and
nutrition. Thus, their presence can be of great benefit to man. On the other hand, some can
cause diseases to man and so there is need to be aware of their nature presence around us.
Requirements
Two petri-dishes
Two plate covers
Glass marking pencil
Transparent tape
Microscope
Agar powder
Permanent slide of bacteria
Bunsen burner/source of heat.
108
Safety
Make sure that the students wash hands with soap and warm water after touching the
plates. Use a disinfectant to wipe down all surfaces where bacteria may have been
deposited. Inform parents that students will be doing laboratory activities that involve
bacteria so parents of students with compromised immune system may wish their children
not to do the laboratory activities. For safe disposal, soak the plates overnight in undiluted
chlorine breach.
Procedure
i.
ii.
iii.
iv.
v.
vi.
Prepare agar medium by boiling a mixture of 10g of agar powder with 50ml of water
Label two petri- dishes ‘control’ and ‘exposed’ in which you pour prepared agar
medium.
Cool both plates for 20 minutes until the medium hardens.
Tape closed the cover of the control plate. Remove the cover of the exposed plate.
Leave both plates for 5 minutes. Do not touch or breathe on the agar.
After five minutes, tape closed the lid of the exposed plate. Store both plates upside
down in a warm place.
After two days record the number of bacteria colon on each plate.
Caution: do not open the plates. Give them to your teacher for disposal.
1. Which plate had more colonies?
2. Where did bacteria on your plates come from? Explain your answer.
3. Carefully observe the two colonies and make any comparison if any, with the
permanent slide of a bacterium as seen under a light microscope.
4. Using a microscope, observe and draw a structure of bacterium on the permanent
slide. Use charts to label your drawing.
109
1. The exposed plate.
2. Bacteria spores and dust borne bacteria landed on the plate when it was exposed.
3. Both clones look alike under open eyes.
4. The most likely specimens to observe include the following:
Figure 32: The most common specimens of bacteria
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Activity 2: Classification of bacteria (50 minutes)
Specific objective:
Differentiate between the two groups of bacteria.
Introduction
Traditionally, bacteria are classified on the basis of their shape into five groups. These are;
- Bacilli-rod shaped
- Cocci-spherical or oval shaped
- Spirilla-corkscew shaped rods.
- Spirochaetes-corkscrew with long thin flexible bodies
- Vibros-comma shaped.
The prefix diplo indicates bacteria normally exist in pairs, strepto, normally stick together
to form chains and staphylo, normally stick to gather to form grape-like bunches.
New methods were later introduced by hans christain gram using a staining technique that
is widely used to classify bacteria into two major groups each comprising a wide variety of
different species. Those that stain purple after treatment with grams stain are said to be
gram-positive whereas those that stain pink are gram-negative.
Rationale
The classification of bacteria is quite useful because it helps us to identify the different
groups of bacteria and their response to antibiotics such as penicillin and drugs. This is an
important component in medicine since different bacteria cause different diseases and so a
need to know how each type responds to chemicals.
Requirements
Slide
Inoculating loop
Bunsen burner
Forcep
Two glass rods
Staining tray
Dropper
Live yoghurt
Timer
Microscope
Procedure
i. Smear live yoghurt thinly over a glass slide
ii. Air-dry and then pass the slide through a yellow bunsen burner flame.
iii. Stain with crystal violet and leave for 30 seconds.
iv. Rinse with lugos’ iodine and leave for 30 seconds.
v. Rinse with distilled water
111
vi.
vii.
viii.
ix.
Flood with acetone-alcohol and leave for three seconds.
Rinse with distilled water.
Counter-stain with safranin and leave for one minute.
Blot dry and examine under a microscope.
1)
Write down your observation when the prepared slide is observed under light
microscope under high power.
2)
Try to account for the results in number one above?
3)
What is the importance of the gram reaction?
112
Figure 33: Observation of gram-positive and gram -negative bacteria under microscope
1.
2.
After treatment with gram stain, the purple and pink colours are observed.
Purple colour after treatment indicates gram-positive bacteria whereas the pink
colour indicates gram-negative bacteria due to difference in cell wall structure of
two types of bacteria.
3.
The gram reaction is quite useful because gram-positive bacteria tend to be
sensitive to antibiotics such as penicillin and drugs while gram-negative are
insensitive to antibiotics and so cannot be used to combat infection by these
bacteria using the same drugs. These forms of bacterium are common in yoghurt.
113
Chapter 6: Animal kingdom
Kingdom animalia is another large group made of thousands of organisms which are all
multicellular, eukaryote and that have heterotrophic nutrition, usually by ingestion. They
have no cell wall, no sap vacuole or plastid. Reproduction is mainly sexual. Kingdom
animalia includes invertebrates and vertebrates. The relevant distinctive feature between
invertebrates and vertebrates is that the latter have a spinal cord and an endoskeleton.
Activity 1: Identification of main animal phyla (50 minutes)
Specific objective
Identify main phyla of animal kingdom according to specific features of each phylum.
Introduction
The animal kingdom is subdivided into phyla, which in turn are subdivided into smaller
groups. The members of each phylum, though often displaying considerable diversity of
form, are held together by certain features which they all posses.
The purpose of this investigation is to examine representatives of each major phylum. In
doing this, students are urged to notice the variety within each phylum, but also more
obvious features uniting various members.
Rationale
Organisms are diverse in nature. Human beings interact with various organisms which are
economically important in our lives and the biodiversity of environment. Thus, there is
need to understand the diversity of living organisms.
Requirements
Sweep nets
Specimen bottles
Pins
Microscope
Permanent slides
Charts
Models
Hand lens
Forceps
Petri dishes
Preserved specimens
Surgical blades
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Cotton wool
Labels
Insecticides
Formaldehyde
Precaution
Some organisms are poisonous, some have spikes and others are able to sting. Care must be
taken while handling them
Procedure
i.
ii.
iii.
iv.
Collect various animals (use charts or models where it is difficult to find the animal),
that represent their respective phyla from an identified environment using
appropriate apparatus. The specimens collected shall be labeled for easy
identification.
Observe and familiarize themselves with the specimens before starting the
experiment to minimize errors.
Classify the named organisms in different phyla using observable characters that
suit them.
Preserve some specimen for future use.
Sponges (sycon ciliatum)
Cnidaria (jellyfish)
Platyhelminthes(flatworm)
Nematoda (trichris trichiura)
Annelid (lumbricus)
Arthropod (butterfly)
Mollusk (slug)
Echinodermata (starfish)
Figure 34: Examples of different animals
115
Chordate (lungfish)
The expected observable features phyla of animals and their features are the following:
I. Phylum porifera (sponges)
Main features
Sponges are sessile, multicellular animals that lack true tissue and a definite symmetry.
Most species are marine and only a few live in fresh water.
The outer layer is made up of epitherial or epidermal cells. Some epitheliac cells are
modified to form porocytes which control the size of the pores and regulate water flow.
The inner layer is made up of flagellated cells called choanocytes. These cells function in
the feeding process.
Sponges reproduce asexually and sexually.
Examples of porifera: sycon, leucosolenia, euplctella, hyalonema, cliona , euspongia
II. Phylum cnidaria
Main features
Cnidaria are aquatic animals, typically diploblastic with a radial symmetry.
They have a jelly –like layer between the ectoderm and the endoderm. This is the
mesogloea.
There is a single opening which functions as the mouth and anus.
They exist in two basic forms, polyp (as a cylinder) and medusa (like an umbrella).
They also reproduce asexually and sexually.
Examples of cnidaria are hydra obelia, jellyfish (aurelia), sea anemones, corals.
III. Phylum platyhelminthes (flatworms)
Main features
They have flattened bodies, dorso-ventrally.
Posses a mouth but no anus.
They possess a scolex.
They have ploglitides.
Examples of organisms from this phylum are: planaria which are free living worms;
schistosoma haematobium which causes schistomiasis (bilharzias); fasciola hepatica that
destroy the liver, and taenia saginata that attack the gut of the organism and cause
anaemia.
IV. Phylum nematoda (roundworms) main features
The organisms have narrow bodies which are pointed at both ends.
The organisms are rounded.
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They posses thick elastic cuticle.
Examples of organisms from this phylum are:
Ascaris lumbrocoids: are large worms and are parasitic in gut of human and pig
Hook worms, these are harmful parasites; trichuris trichuria, entorobius vermicularis.
V. Phylum annelida
Main features
They have metemeric segmentation.
They have septa which is sheet-like, that separates one segment to another.
They posses chaetae which is bristle-like, attached to each segment which act as legs.
Examples of organisms from this phylum are: lumbricus terrestris and hirudo medicinalis.
Vi. Phylum arthropoda
Main features
Most arthropods have chitinous cuticle which have varied degrees of hardness.
They have jointed appendages.
They have exoskeleton i.e. Muscles are attached to the cuticle.
They undergo ecdysis or moulting to allow growth.
Some groups have a compound eye for vision.
Examples under this category include: mosquito, tsetse fly, locusts, bees, butterfly; ticks
and millipedes.
Vii. Phylum mollusca
Main features
They have a ventral muscular foot used for movement.
The body organs are concentrated as a visceral mass above the foot.
A mantle, which is a heavy fold of tissue, wrapped around the visceral mass and overhands
it this forms a mantle cavity, which houses the gills, anus and excretory pores. The mantle
also contains glands that secrete the shell made up of calcium carbonate.
Many molluscs have an open circulatory system where blood bath the tissue directly.
Excretion ids carried out by one or two nephridia which are tubular structures.
Examples under this category include: garden snail (helix), slug (limax), mussel, and
cuttlefish.
Viii. Phylum echinodermata
Main features
Echinodermas are triploblastics, unsegmented organisms of the marine environment.
The larval forms display bilateral symmetry. However, this is replaced by pentaradial or
pentameric symmetry in adults.
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They have endoskeleton composed of hard calcium plates called ossicles just under the
skin.
They possess a water vascular system which is a network of fluid –filled canals that are
connected to numerous tube feet.
The water vascular system is used in a number of processes, for example, locomotion,
respiration and feeding.
Examples under this category include: starfish, sea lilies, bristle stars, sea urchin sea
cucumber.
Ix. Phylum chordata
Main features
They have notochord, which is dorsally situated, strengthening rod.
Presence of pharyngeal clefts.
They have segmented muscle blocks (myotomes).
Presence of post-anal tail.
Examples under this category include:
Fish (lung fish) - Protopterus aethiopicus
Man – Homo sapiens
Lizards - heloderma suspectum
Hen - Gallus domestica
Frog - Rana tempolaria
From the above information, we can conclude that, kingdom animalia is made up of several
phyla. This shows that they are similar as they belong in the same kingdom. On the other
hand, the organisms belong to different phyla with different features. Thus, they are
different.
Discussion question
Q1). What are the main features in phylum chordate?
118
They have notochords which are dorsally situated.
Pharyngeal clefts.
Segmented muscle blocks (myotomes).
Post- anal tail.
They have red blood.
119
Activity 2: Classification of arthropods into classes (100 minutes)
Specific objective
Differentiate features of different organisms under phylum arthoropoda, classify them into
classes and orders.
Introduction
The phylum arthropoda is subdivided into classes, which in turn are subdivided into
orders. The members of each class or order, though often displaying considerable diversity
of form, are held together by certain features which they all posses. The purpose of this
investigation is to examine representatives of each major class and order. In doing this,
students are urged to notice the variety within each class or order, but also more obvious
features uniting various members.
Rationale
The study of arthropods, require wide range of knowledge on their structures. With that
knowledge, man can use them for his benefit and for the environment as whole.
Requirements
Sweep nets
Specimen bottles
Pins
Microscope
Permanent slides
Charts
Models
Hand lens
Forceps
Petri dishes
Preserved specimens
Surgical blades
Cotton wool
Labels
Insecticides
Formaldehyde
Precaution
taken while handling them.
120
Procedure
i.
ii.
iii.
iv.
v.
vi.
Collect various organisms in phylum arthropoda (use charts or models where it’s
difficult to find the organisms), that represent their respective classes and orders from
an identified environment using appropriate apparatus.
The specimens collected shall be labeled for easy identification.
The students shall then observe and familiarize themselves with the specimens before
starting the experiment to minimize errors.
They shall classify the named organisms in different phyla using contrasting characters
that suit them.
Preserve some specimen for future use.
Tabulate characteristic features of the collected organisms as shown below:
The phylum arthropoda is made up of several classes and orders. This shows that they are
similar as they belong in the same phylum. On the other hand, the organisms belong to
different classes and orders with different features. Thus, they are different as shown in the
table below.
Table 14: Main orders of arthropods
Class
1. Insecta
- have three body
parts
- have three pairs of
legs
- have 2 antenna
Order
1. Dictyoptera
- dorsally-ventrally flattened
body
- leathery fore wings
- membranous hind wings
Examples
2. Diptera
- they have a pair of wings.
- they have halteres for
balancing
- their mouth parts are
modified for sucking, piercing
and biting.
- they have complete
metarmorphosis
House fly (Musca domestica);
mosquito (Anopheles spp,
Aedes albopictus)
Cockroach(blatta orientalis)
Tsetse fly ( Glossina
morsitans)
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3. Coleoptera
- they have two pairs of wings.
The fore wing is horny. The
hind wing is membranous.
Mouths parts are adapted for
biting and chewing.
Bean weevil (Acanthoscelides
obtectus);
Maize weevil (Stophilu, zea
mays and Tribolium
castaneum)
4. Hymnoptera
- they are social insects,
- they have four membranous
wings.
- their mouth parts are adapted
for chewing or sucking and
lapping
- abdomen is constricted
- ovipositor always present and
modified for sawing, piercing
or stinging.
5. Lepidoptera
- they have four wings covered
with tiny scales. They have a
coiled proboscis for sucking
nectar
Family; formicidae , (ants)
Family;apidae, (Apis mellifera
,the bees)
Family; vespidae;(
Vespa orientalis, the
Wasps)
Family; Papillionidaeie,
Papilio drdanus i.e. The
butterflies
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Family; noctuidae i.e. Noctua
pronuba, the moths
Class
Order
Example
2. Diplopoda
- they have
cylindrical body
- they are
herbivores
- they have no
poison
- they have simple
eyes
- they have two
pairs of legs per
segment
Spirobolida
- Its members are
distinguished by the
presence of pronounced
suture that runs vertically
down the front of the head
- Most of the species live in
the tropics and many are
brightly colored
Millipede
(Narceous americanus)
3.Chilopoda
- dorsal venterally
flattened body
- two tagmata
(head and trunk)
- one pair of legs
per trunk segment.
- one pair of
mandibles and two
pairs of maxillae
- clawlike poison
jaws or fangs with
which centipedes
paralyze their prey.
- eyes may be
present or absent.
Order lithobiomorpha - stone
centipedes
Stone centipede
one pair of antennae with 14 or more segments
Order geophilomorpha - soil
centipedes
Soil centipede
Order scutigeromorpha house centipedes
House centipede
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Order scolopendromorpha tropical centipedes
4.Crastecea
Tropical centipede
Order decapoda
- Cephalothorax
and abdomen
- Two pairs
antenna
- Five pairs of
legs on
cephalothorax;
The first pair
usually with a
large claw
Lobsters,
Crayfish,
Crabs,
5.Arachnida
- they have
abdomen which is
1. Araneae
124
secondarily
unsegmented and
separated from
cephalothorax by a
waist like
constriction,
chelicerae contain
poisonous glands;
they have simple
eyes
Spiders
2. Acarina
Ticks
Mites
3. Scorpionida
Scorpions
1.
2.
State the main classes of arthropods giving an example in each case
With reference to the table, state three structural differences between a spider
and a bee.
125
1.
Insecta- bee
Arachnida- spider
Crastecea-crab
Diplopoda-millipede
Chilopoda- centipede
2.
Reference should be made in the table 14 above.
126
Activity 3: Identification of a typical insect (20 minutes)
Specific objective
Observe and identify external features of an insect.
Introduction
Insects have more species than all other forms of life combined. They are found in almost
every habitat i.e. water, land and air. A typical insect has three body parts, three pairs of
legs and one pair of antenna. Some insects have wings and others don’t have. Their life
cycle is always characterized by complete metamorphosis (e.g. butterflies, bees, ants,
wasps) or incomplete metamorphosis (e.g. cockroaches, grasshopper, termites and bugs).
Rationale
The study of insects requires wide range of knowledge on their structures. With that
knowledge, man can use them for his benefit and for the environment as whole.
Requirements
Sweep nets
Specimen bottles
Pins
Microscope
Permanent slides
Charts
Models
Hand lens
Forceps
Petri dishes
Preserved specimens
Surgical blades
Cotton wool
Label
Insecticides
Formaldehyde
Precaution
taken while handling them.
Procedure
i. Collect specimens of insects from an identified environment using appropriate
apparatus.
ii. Labeled collected specimens for easy identification.
Select one of the specimens and identify features on its head and thorax.
127
Drawing and labeling the main features of an insect shall be represented as shown below:
Figure 35: The body parts of a butterfly and locust
From the above diagrams it is concluded that all adult insects have three main body parts—
the head, which holds an insect’s primary sense organs; the thorax, which is the attachment
site for the legs and wings; and the abdomen, which contains the organs for digestion and
reproduction. All of the insect’s soft inner body parts are protected by an external skeleton,
or exoskeleton, made of semi rigid plates and tubes.
What features can we refer to classify an arthropod as an insect?
128
Suggested answer to discussion question
They have three body parts, three pairs of legs and compound eyes.
129
Activity 4: Observation of mouth parts of insects (50 minutes)
Specific objective
Observe and identify mouth parts of insects.
Introduction
There’s a wide variety of feeding techniques in insects which involve use of different
mouthparts. These varieties of mouthparts are adapted for different types of food.
Therefore, the investigations to be carried out involve various insects, whose mouthparts
are adapted for piercing, sucking, biting and chewing.
Rationale
Knowing the feeding habits of insects helps man to understand transmission of pathogens,
thereby understanding how to control or eradicate diseases caused by the named
pathogens. On the other hand the understanding shall enable man to formulate insecticides
that control the insects which damage crops.
Requirements
Sweep nets
Specimen bottles
Pins
Microscope
Permanent slides
Charts
Models
Hand lens
Forceps
Petri dishes
Preserved specimens
Surgical blades
Cotton wool
Potassium hydroxide solution
Slides
Labels
Grasshopper/locust, mosquito, butterfly
and housefly
Insecticides
Formaldehyde
Precaution
Procedure
i.
ii.
Collect a large grasshopper or locust from an identified
appropriate tools
Remove the head from a dead grasshopper / locust
130
environment using
iii.
iv.
v.
vi.
vii.
Put the head in a test tube containing a dilute solution of potassium hydroxide and
boil the head gently for 5 minutes to soften it and make it transparent.
Remove the head and wash it several times.
Remove mouth parts starting with the labrum; use the forceps to remove each part
by pulling it gently from their attachment in the following order: labrum, mandibles,
two maxillae and finally the labium.
Examine the mouth parts under a light microscope. Put the detached parts in dilute
glycerine and mount each part on a separate slide.
Repeat the above steps using a butterfly, a housefly and mosquito. But for the
butterfly, mosquito and housefly the head should be cut and mounted on the
microscope for easy observation.
131
Figure 36: Diagrams showing mouth parts of insects
From the above results it can be concluded that insects have mouthparts which are adapted
for piercing, sucking, biting and chewing.
132
Table 15: Types of mouth parts of insects
Insect
Type of mouth part
The grasshopper / locust,
Mandibles for cutting and chewing plant tissues.
The mosquito
Adapted for sucking, piercing and biting
The butterfly
Coiled proboscis for sucking nectar.
The housefly
Adapted for sucking, piercing and biting
You are provided with a specimen k, a hand lens, a razor blade, a pin and a dissecting plate.
Observe the specimen using the hand lens and answer the questions that follow.
a)
(i) To which class of arthropods does the specimen k belong?
(ii) Give any three features that support your answer.
b)
Describe the eyes of the specimen k and give any one advantage of this type of
eyes.
c)
Observe the mouthparts of the specimen k and then describe its adaptations for
feeding.
d)
To which order does the specimen k belong? Give any two reasons.
e)
Use the razor blade to cut off the head of the specimen k and you draw and label.
133
Note to the teachers’. The specimen k should be a grasshopper. This is an extra activity
for students.
(i) The specimen is an insect
(ii) Reasons:
 The body is made of three main parts,
 The body has three pairs of legs,
 Well-developed compound eyes
a)
The specimen k has compound eyes. These allow the specimen having a wide
visual sphere or they improve the visual acuity.
b)
The specimen k has mouth parts adapted to chewing.
c)
Lateral (side) view of the head of the specimen k
Figure 37: Magnification: x 10
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Activity 5: Observation of insects’ wings and hind limbs (50 minutes)
Specific objective
Classify insects according to the nature of hind limbs, and number of wings.
Introduction
There’s a wide variety of insects’ wings. These varieties of wings are of different types and
patterns. Therefore, the investigations to be carried out involve the use of numbers,
patterns of these wings to classify insects into their orders.
Rationale
Insects do not have the same pattern and number of wings. And so, the type of wings
determines the length, the sound produced, power, and maneuvering in flight. These
features help in classifying insects into different orders.
Requirements
Sweep nets
Specimen bottles
Pins
Microscope
Charts
Models
Hand lens
Forceps
Petri dishes
Surgical blades
Cotton wool
Slides
Labels
Grasshopper / locust, mosquito, butterfly
and housefly
Insecticides
Formaldehyde/chloroform
Precaution
Procedure
i.Collect a large grasshopper or locust, mosquito, butterfly and the housefly from an
identified environment using sweep nets.
ii.Use insecticide to immobilize the collected insects, once in specimen bottles.
iii.For each of the collected insects, examine the wing appearance and their number using
hand lenses.
iv.Detach the hind limb from the grasshopper or locust. Draw and label its parts.
135
v.Fill the table below, by using the wing features for each insect:
vi.Use the formaldehyde or chloroform to preserve the collected species if necessary.
Table 16a: Types of insect wings
Insect
Type and number of
wings
The grasshopper / locust
The mosquito
The butterfly
The housefly
136
Order of classification
Interpretation of results and discussion
Table 16b: Types of insect wings (complete)
Insect
Type and number of Order of classification
wings
The grasshopper / locust,
2 pairs: 4 wings,
The mosquito
1 pair: 2 wings, halters for Diptera
balancing
The butterfly
2 pairs: 4 wings with scale
The housefly
1 pair: 2 wings, halters for Diptera
balancing
Orthoptera
Lepidoptera
The hind limb of the grasshopper or locust is as shown below
Figure 38: Structure of hind limb of an insect
Discussion question
With reference to the structure of the wings and hind limbs of the grasshopper or locust,
suggest its mode of locomotion.
137
The grasshoppers and locusts are adapted for flight and hopping. However, since their
outer pair of wings is harder than the inner one, flight is not powerful. But as the hind limbs
are long and muscular than the fore limbs, their hops are higher.
138
Activity 6: Differentiation of vertebrate groups (50 minutes)
Specific objective
Differentiate the five classes in the phylum chordata.
Introduction
There are five main classes in the phylum of chordate: fish, amphibians, reptiles, birds and
mammals. Vertebrates or chordates make up a wide phylum characterized by the following
common features:
Presence of notochord, which is dorsally situated, strengthening rod
Presence of pharyngeal clefts
Bilateral symmetric body
Segmented muscle blocks (myotomes)
Presence of post-anal tail
Rationale
When looking around, we will see animals with different structures and forms. As over a
million species of vertebrates have been found, the need for classification becomes crucial.
By making a critical analysis of these features, one is able to see how, though similar,
different vertebrates belong to different classes as a result of their features and habitats
they occupy.
Requirements
Charts/ photographs
Soft rubber gloves
Lenses
Binocular camera
Thermometer
A fish (tilapia)
A frog or toad
A lizard
A hen
A rat or rabbit
Dissection tray
Dissection set
Surgical blades
Scissors, pins
Formaldehyde or chloroform
Cotton wool
Forceps
Glass jar
139
Procedure
A. Habitat
i. Observe the following specimens and compare their habitats: a rat, a fish (tilapia), a
frog or toad, a lizard, a hen, a guinea pig or rabbit.
B. Body temperature
i. Keep the following animals in a room for 1 hour then record their body temperatures:
frog, hen and guinea pig. All specimens should be alive.
ii. Shift your specimens outside the room for one more hour and record their actual body
temperatures.
C. Skin texture
i. Observe the skin textures of the following specimens: a fish (tilapia), a frog or toad, a
lizard, a hen, a guinea pig or rabbit.
ii. Identify structures that cover the skin of each specimen
D. Locomotive appendices
i. Identify the appendices that determine the mode of locomotion of each specimen.
E. Heart cavities
i.
Suffocate a rat in a glass jar containing formaldehyde/chloroform soaked in
cotton wool for 10 minutes.
ii.
Remove the specimen from the jar and place it on a
dissection board and lay it on its back.
iii.
Stretch and pin the limbs of the specimen on
dissection board,
iv.
Pinch the skin in the middle abdomen and cut it
along the middle line to the neck and downward to
the anal opening.
v.
Separate the skin from underlying tissues on other
side of the body using a cutting blade
vi.
Dissect the specimen thoroughly to expose its heart.
vii.
Observe the parts of the heart.
viii.
Repeat the above steps on the hen, the lizard, the
frog and the fish.
ix.
Compare in a table the structure of the hearts of
observed specimens.
Figure 39: Structure of a rat
140
Note: For the frog remember to tie the ventral blood vessel before cutting to avoid excess
bleeding.
Figure 40 Diagram of a rat exposing the heart
The main distinctive features of the specimens observed from the five classes of chordates
can be summarized as follows:
141
Table 17: Distinctive features of selected chordates
Tilapia
Frog
Lizard
In pond
water
Body
Variable /
temperature dependent
on the
environment
In aquatic
medium
Variable /
dependent
on the
environment
On and under
the stones
Variable /
Constant
dependent on 38°c the
39°c
environment
Skin texture
Scaly skin
Dry and scaly
Hairy
Body
appendices
Fins
Slimy and
moist
2 pairs of
webbed
limbs
2 pairs of
short limbs
2 pairs of
limbs
Heart
cavities
1 atrium + 1
ventricle
2 atria + 1
ventricle
2 atria + 1
ventricle
2 atria + 2
ventricles
Habitat
Guinea
Chicken
pig
Terrestrial Terrestrial
Constant
39°c - 40°c
Dry and
feathery
2 pairs of limbs
but the
forelimbs are
modified into
wings
2 atria + 2
ventricles
1)
2)
Give a reason why frogs are rarely found inhabiting dry habitat
Give three advantages homeotherms (e.g chicken) have over ectotherms (e.g
frog) in relation to their body temperature.
3)
Briefly give the advantage of possession of webbed feet in frogs.
4)
Give the advantage which chicken and guinea pig have over tilapia in terms of
their number of heart cavities.
142
1. They use the skin as one of the respiratory organs, thus requiring moist conditions.
2.
i. Metabolism is kept high and so the organism remains active throughout.
ii. Enzyme controlled reactions proceed effectively at optimum temperature
iii. Can exploit a wide range of geographical habitats.
3. Expose large surface area to aid swimming.
4. Increasing number of heart chambers provides the animal with high blood pressure
thus making the supply of requirements to tissues faster.
143
Activity 7: Field trip to a national park, zoos or any convenient local sites (6-8 hours)
Specific objective
Carry out a survey on biodiversities in nearby national park, zoos or any convenient local
sites where variety of species can be identified
Introduction
A park is a conserved environment in which we find biodiversities from the five kingdoms.
Monera, protoctista, fungi, plants and animals are represented in the parks and can be
observed during a national park trip.
Rationale
The national parks are biological treasures that are useful not only for the national citizens
but also for foreigners. Therefore, they need to be regulated for their conservation. It is
important to identify biological specimens that are available in them for classification that
involves; kingdoms, phyla or divisions.
Requirements
Binocular camera,
Sweep net
Specimen bottles
Trip sheet (questionnaires and note
book)
NB. The teacher should prepare in advance the trip sheet containing a table of observed
specimen, their characteristics and if possible their classification.
Procedure
i.
ii.
iii.
iv.
Select convenient sites for study. One site should be open and the other sheltered by
buildings or trees. Another site can be an area or still water and the area of gently
flowing water, or the surface water and the bottom water of the pond or stream.
Record organisms living in each site visited and suggest reasons.
For each observed specimen, attempt to classify it into its kingdom, phylum or
division, class and order if possible.
Map the site, including vegetable zones (grasses, shrubs, trees etc…).
144
Questionnaire
It’s helpful and necessary to have questions as a focus for the teacher and students. Some of
the questions below can be helpful. You can modify some of the questions to suit your
research.
1. Complete the table below:
Table 18: specimen observed in national park /local sites
Specimen name
Habitat
Kingdom
Phylum/ division
Class
2. How many kingdoms are represented by the specimens listed in the table above? State
them and give at least 2 specimens per each.
3. Among all observed specimens, comment on one you liked too much and give reasons.
How can we conserve it?
145
Distribution of practical experiments per term
Term 1: Experiments
Chapter 1: Classification
and diversity of
livingthings
Activity 1: identifying
external features of living
organisms (50 minutes)
Activity 2: construction of a
dichotomous key (100
minutes)
Activity 3: identification of
different organisms in the
five kingdoms(100 minutes)
Activity 4: classification of
the animal groups by
taxonomic hierarchy (50
minutes)
plant groups by taxonomic
hierarchy(50 minutes)
Chapter 2: The plant
kingdom
Activity 1: comparison
between flowering and non
flowering plants (50 minutes
collection time excluded)
between external structure of
monocotyledonous and
dicotyledonous plants (50
minutes)
different leaf modifications
(50 minutes)
Term 2: Experiments
Chapter 3: Fungi
kingdom
Term 3: Experiments
Chapter 5: Prokaryote
kingdom/ monera
Activity 1: observation of
black mould on bread,
Rhizopus nigricans (50
minutes)
Activity 1: microscopic
observation of bacteria (30
minutes)
between bread mould
and penicillium species
(30 minutes)
bacteria (50 minutes)
gill structure of a
mushroom (20 minutes)
Chapter 4: Protoctista
Kingdom
Chapter 6: Animal
kingdom
observation of named
protists(paramecium,
amoeba, euglena, and
unicellular algae) (50
minutes)
main animal phyla (50
minutes)
observation of
permanent slides of
protoctists (50 minutes)
146
arthropods into classes
(100 minutes)
Activity 3: identification a
typical insect (20 minutes)
mouth parts of insects (50
minutes)
inflorescence (1 50 minutes)
Activity 6: dissection of a
drupe (25 minutes)
insects’ wings and hind
limbs (50 minutes)
Activity 6: differentiation of
vertebrate groups (50
minutes )
berry (20 minutes)
types of placentation (50
minutes)
Activity 7: field trip to a
national park (6-8 hours)
typical seed and a maize
grain (25 minutes)
Activity 10: mechanisms of
fruit and seed dispersal (50
minutes)
Activity 11: experiments to
show the conditions
necessary for germination
(set the experiment for a
week)
Activity 12: stages and types
of germination (a week)
Activity 13: demonstration of
asexual reproduction in
plants by cuttings (2 weeks)
Activity 14: demonstration of
asexual reproduction in
plants by fragmentation (3
weeks)
147
Glossary
Adaptation: the development of physical and behavioral characteristics that allow
organisms to survive and reproduce in their habitats.
Agar:
a culture medium based on seaweed extract used in growing organisms in the
laboratories.
Agriculture: a study and practice of cultivating land and growing of crops and rearing of
livestock.
Algae:
any of the various unrelated simple organisms that contain chlorophyll.
Allergy:
an usual sensitivity to a normally harmless substance that provokes a strong
reaction from person’s body.
Alternation of generation: the existence in the life cycle of an organism of two or more
alternative forms or reproductive modes, for example sexual and asexual
cycles.
Angiosperms: a plant in which the sex organs are within flowers and the seeds are in a
fruit.
Antibiotics: substances that destroy or inhibit the growth of microorganisms, particularly
diseases – producing bacteria and fungi.
Baccate:
resembling berry in shape.
Bacciferous: describes plants that produce berries.
Bamboo: a strong hollow stems of a tropical plant used in building, furniture, canes
fishing rods, etc
Basidiospores: a spore produced by a basidiomycote fungus such as mushroom, puffball,
smut or rust.
Berry:
a small juicy or flesh fruit
Bilocular: involving or using both eyes, or relating to vision using both eyes.
Biodiversity: the range of organism present in a particular ecological community or
system.
Bluebell: a woodland plant of lily family with long thin leaves.
Bryophyte: a non flowering plant, often growing in damp places that have separated
gamete- bearing and spore – bearing forms. Eg moss.
Buds:
the apical meristem of a shoot surrounded by leaf primordial and sometimes
enclosed in scaly leaves.
Buttercup: a plant that grows in grassland. Flowers yellow: cup shaped.
Carpels:
a female reproductive organ in a flower, enclosing the fertilized ovules that are
developing in two seeds
Chaetae: a bristle that occurs singly or clusters in worms such as earth worms and clam
worms and helps them to move.
Cherry:
a small round fruit that has a single hard pit and varies in colour from bright
red or yellow to dark purplish black.
Chloroplasts: any of the chlorophyll containing organelles that are found in large numbers
in those plant and algal cells undergoing photosynthesis.
Ciliates:
a phylum containing ciliated protozoans.
148
Columella: a tiny bone in the middle ear of all land vertebrates that transmits sound
waves from the ear drum to the inner ear and correspond to the stapes in
mammals.
Conifers: seed bearing plants including pines whose gametes are carried in cones
Cross pollination: transfer of pollen form an anther to a stigma of a different flower of the
same species.
Cryptogams: an organism such as a fern, moss, algae, or fungus that reproduces by means
of spores instead of seeds.
Cucumber: a long fruit with dark green peel and crisp white watery flesh that is usually
raw in salads and sandwiches or pickled.
Cytoplasm: the complex of chemical compounds and structures within a plant or animal
cell excluding the nucleus.
Dandelion: a weed with bright yellow flowers on hollow stalks that produce fluffy white
seed heads.
Dehiscence: the spontaneous and often violent opening of a fruit, seed pods, or anther to
release and disperse the seeds or pollen
Dormancy: an inactive period in the life of an animal or plant during which growth slows
or completely ceases.
Drupe:
a fruit with a thin outer skin, soft pulpy middle and stony central part that
encloses a seed.
Ecdysis or moulting: the regular molting of an outer layer by arthropods such as insects
and crustaceans and by reptiles.
Embryo: an organism in its earliest stages of development form the time when the
fertilized ovum starts to divide.
Enzymes: a protein that acts as a catalyst in biochemical reactions.
Epicotyl: the region of the seedling stem above the stalks of the seed leaves of an
embryo plant.
Epigeal germination: seed germination in which the seed leaves emerge from the ground
and function as true leaves.
Eucalyptus: an evergreen tree with aromatic leaves and produces timber, resin and
medicinal oil.
Euphobia: plant with milky juice such as spurge.
Exoskeleton: a rigid external covering for the body in certain animals, such as the hard
chitineous cuticle of arthropods.
Fertilization: the fusion of male and female haploid gates to form a diploid zygote.
Flagella: a whip-like organ of locomotion, single, paired or many, found in motile algae
and gametes.
Fragmentation: a method of asexual reproduction, occurring in some invertebrate animals
in which parts of the organism break off and subsequently differentiate and
develop into new individuals.
Funicle:
the stalk that attaches an ovule to the placenta in ovary of a flowering plant.
Gametophyte: the generation in the lifecycle of a plant that bears the gamete
producing sex organs.
149
Germination: the initial stages in the growth of the seed to form a seedling. Or the first
signs of growth of spores and pollen grains
Gymnosperms: a woody vascular plant in which the ovules are carried naked on the scales
of a cone.
Habitat:
the natural conditions and environment in which a plant or animal lives such
like forest desert wet lands etc.
Hetetrophic: obtaining nourishment by digesting plant or animal matter, as animals do, as
opposed to photosynthesizing food, as plants do.
Hilum:
a scar on the seed of the plant indicating where it was attached to the ovule.
Homoiotherms: organisms that generate heat within the body and generate body
temperature by physiological means.
Hormone: a chemical secreted by an endocrine gland or some nerve cells that regulates of
the specific tissue or organ. In plants, it is substance synthesized by plants that
regulates growth and development.
Horticulture: the science, art, technology and business involved in intensive plant
cultivation for human use. It involves plants for food (fruits, vegetables,
mushrooms, culinary herbs) and non-food crops (flowers, trees and shrubs,
turf-grass, hops, grapes, medicinal herbs).
Horticulture: the science, skill, or occupation of cultivating plants especially flowers, fruits,
and vegetables, in gardens or green houses.
Hyphae: parts of the vegetative portion of a fungus that resembles threads.
Hypocotyls: the part of an embryo plant that lies between it cotyledons and its radical
Hypogeal germination: describes a plant that remains below ground while the stem of the
plant grows
Indehiscent: describes a fruit that does not open up to release seeds when ripe.
Inflorescences: a flowering structure that consists of more than one flower and usually
comprises distinct individual flowers.
Legume: a seed, pod or other part of a plant such as a pea or bean used as food
Lichen:
a complex organism consisting of fungi and algae growing together in
symbiosis that often appears as grey, green, or yellow patches on locks trees
and other surfaces.
Locule:
a small cavity, chamber, or cell in plant or animal.
Locust:
a migratory grasshopper that often swarms and devours crops and vegetation.
Magnification: the process of causing an object or image to appear larger than it really is,
especially by using a lens or microscope.
Membrane: a thin flexible sheet of tissue connecting, covering , lining or separating
various parts or organs in animal and plant bodies, or forming the external
wall of the cell.
Metameric: a body divides into a series of similar segments metameres
Metamorphosis: a rapid transformation from the larval to the adult form that occurs in the
lifecycle of many invertebrates and amphibians.
Millipedes: a small plant- eating arthropod with a tubular body made up of segments,
most of which have two pairs of legs.
150
Modifications: a slight change or alteration made to improve something or make it more
suitable.
Multilocular: consisting of or having several different chambers or cavities.
Mycelium:a loose network of the delicate filaments hyphae that form the body of fungus,
consisting of the feeding and reproducing hyphae
Nourishment: food or valuable substances in food that an animal or plant requires to live,
grow, or remain fit and healthy.
Nucleus: the central body, usually spherical, within a aukaryotic cell, that a membraneencased mass of protoplasm containing the chromosomes and other genetic
information necessary to control cell growth and reproduction.
Oat:
a plant with edible seeds that is grown as a cereal crop.
Offspring: animals young, or sometimes a descendant of a plant
Ovary:
for plants, it is the lower part of pistil that bears ovules and ripens into a fruit.
For either of the two female reproductive organs that produce eggs, and in
vertebrates, also produce the sex hormones estrogen and progesterone.
Oxalis:
a genera plant with leaves divided into three parts similar to those of clover for
example wood sorrel
Parasites: a plant or animal that live or in another, usually larger, host organism in a way
that harms or is of no advantage to the host.
Parsley:
a widely cultivated plant of the carrot family with small compound leaves
Penicillium: a bluish –green fungus that grow on stale or ripening food.
Pericarp: the part of a fruit that develops from ovary wall of the flower.
Petals:
one of the parts of the flower that make up the corolla.
Phanerograms: flowering plants
Phytoflagellates: plant flagellates with one or more flagella and feed by photosynthesis
Pileus:
the umbrella shaped cap of certain fungi such as mushrooms.
Placenta: a ridge of tissue on the ovary wall of flowering plants to which the ovules are
attached
Planaria: a free-living flat worm
Plantain: a large plant of the banana family that produces plantains or a green fruit
resembling a banana, eaten cooked as a steple food in many tropical countries.
Ploglottides: flat segments on a tape worm which bud off from the narrow region behind
the scolex
Plumule: the part of the embryo that develops into a shoot system.
Poikitherms: organisms that absorb heat from the environment and regulate body
temperature by behavior means.
Prokaryotes: any organism in which the genetic material is not enclosed in a cell nucleus.
Radicle:
the part of the embryo that develops into a root system.
Recycling of nutrients: the use and reuse of nutrients by organisms.
Rhizoids: colorless hair like outgrowth found in certain algae and gametophytes
generation of bryophyte and ferns. They anchor the plant to the substrate and
absorb water and mineral salts.
Sarcodina: a phylum of protozoans that move by pseudopodia and feed by phagocytosis.
151
Schistosoma: genera of parasitic flatworms in the blood of birds and mammals. In humans
it causes a disease schistosomiasis
Scolex:
a head bearing suckers and hooks for attachment of the flatworm to the hosts’
body.
Seed dispersal: the spreading of fruits and seeds from the parent plant distant places.
Self pollination: the transfer of pollen from an anther to a stigma of the same flower.
Sepals:
the lowermost perianth segments especially when green, and thus
distinguished from petals.
Sporangia: reproductive structure in plants that produces asexual spores.
Sporangiophore: a simple or branched stalk that bears one or more sporangia.
Spore:
a unicellular, asexual, reproductive cell usually uninucleate.
Sporophyte: the generation in the life cycle of a plant that produces spores. The
sporophyte is diploid but spores are haploid. It is either completely or partially
dependant on the gametophyte generation in mosses and liverworts, but is the
dominant plant in the life cycle of clubmosses, horsetails, ferns and seed plants.
Sporozoa: a phylum of parasitic protists whose members may have a number of different
animal hosts.
Stamen:
one of the male reproductive parts of the flower with anther head and filament.
Stipe:
the stalk that forms the lower portion of the fruiting body of certain fungi such
as mushrooms and supports the umbrella shaped cap.
Stolon:
a long aerial side stem that gives rise to a new daughter plant when the bud at
its apex touches the soil.
Stomata: a pore in the epidermis bounded by a pair of guard cells.
Succulent fruits: fruits that have a fleshy part and can be eaten.
Taxonomy: the study of the theory, practice and rules of classification of living and extinct
organisms.
Tegmen: a covering part in a plant or animal.
Tendrils: a slender branched or unbranched coiled modified stem, leaf or leaflet that
responds to contact with solid objects by twinning around them.
Terrestrial plant: land plants.
Testa:
hard outer covering of a seed.
Tracheophytes: any plant that has elaborate tissue, including vascular tissue; a
conspecuous, saprophyte generation; and complex leaves with water proof
cuticles. Tracheophytes include plant of the phyla psilophyta, lycophyta,
sphenophyta, filicinophyta, coniferophyta, and anthophyta. In traditional
classification systems these are were regarded as classes of the division
tracheophyta.
Transpiration: the loss of water vapour from the plant mostly from the leaves.
Vegetative propagation: a form of asexual reproduction in plants where by new
individuals develop from specialized multicellular structures that become
detached from the parent plant
Zooflagellates: a colorless protozoan that ingests organic matter, is often parasitic, and
has one or more flagella.
Zygote:
a diploid cell formed by the fusion of male and female gamete at fertilization.
152
Bibliography
1. Aziz. (1995). KCSE revision biology.
2. Chenn, P, Murray, J. (1999). Microorganisms and biotechnology.
3. Kaddu, J et al. (1999). Biology for east africa, 1st edition, published by cambridge
university press.
4. Lee, C. (2008). Biology volume 2, pre –u text stpm, pearson, longman.
5. Roberts, M.B.V, King, T.J. (1987). Biology, a functional approach student’s manual. 2nd
edition.
6. Miller, l. (2008). Biology teachers’ edition, prentice hall.
7. Mineduc/NCDC. (2010). Advanced level biology curriculum: principal subject, form 4, 5 &
6.
8. Neil, A. & Campbell et al. (2008). Biology, 8th edition.
9. Oxford university press. (2000). Dictionary of biology, the world’s most trusted reference
books.
10. Stone, R.H. et al. (1981). New biology for tropical schools, 3rd edition.
11. Soper, R. (1995). Biological science, 2nd edition, cambridge, london.
12. Wachira, G. (2007). KCSE golden tips biology practical manual.
13. Apstumbo.hubpages.com: sponges
14. Ehow.com : flatworms
15. Butterf36.blogsport.com: phylum nematode
16. Biologycorner.com: phylum annelid
17. Thaigoodview.com: phylum arthropoda, butterfly
18. Singingsandsbb.com: echinodermata , starfish
19. Natuurlijkmooi.net: sycon ciliatum
153

biology practical manual for form four

Transcription

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