Ch 16 Coordination in humans Exercise

New Senior Secondary Mastering Biology (Second Edition)
Book 2
Ch 16 Coordination in humans
Exercise
Multiple-choice questions (p. 16-33)
1 A
6 C
11 A
2
7
D
B
3
8
A
B
4
9
A
B
5 C
10 C
Short questions (p. 16-35)
12 HKALE Biology 2009 I Q1
13 HKCEE Biology 2008 I Q2
(a) To harbour more neurones (1)
(b) Y: * medulla oblongata (1)
It acts as the reflex centre for some reflex actions /
It controls involuntary actions (1) any one
(c) Motor area (1)
(d) Sensory area (1)
Total: 5 marks
14 a
b
c
d
Correct drawing to show dendron of sensory neurone starts at receptor and travels
through dorsal root; cell body is drawn inside dorsal root ganglion and axon enters grey
matter of spinal cord (1)
Muscle (1)
Reflex action produces fast response / protects the body from danger / protects the
body from damage. (1)
Reflex arcs connect with other neurones to transmit nerve impulses to the brain. (1)
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 Oxford University Press 2014
New Senior Secondary Mastering Biology (Second Edition)
Book 2
15 HKDSE Biology 2013 IB Q1
B (1) C (1) A (1)
(3 marks)
Structured questions (p. 16-36)
16 a
b
17 a
b
c
P: mitochondrion (1)
Q: nucleus (1)
R: myelin sheath (1)
i By diffusion (1)
from a high concentration to a low concentration. (1)
ii The chemicals may change the shape of the active sites of the enzymes, (1)
or bind to the active sites of the enzymes. (1)
Neurotransmitter molecules cannot bind to the active sites of the enzymes. (1)
The breaking-down reaction of the neurotransmitter molecules cannot be
catalysed. (1)
The cerebral hemisphere is the site for intelligence / sight / hearing / enables us to think
/ make decisions / have memories / controls voluntary actions. (1)
The cerebellum coordinates muscular movements / maintains body balance. (1)
Death may result. (1)
Part C controls involuntary actions / controls breathing / heart beat. (1)
Spinal cord (1)
There will be no impulses below the cut-position / at the lower body. /
There will be no sensation below the cut-position. /
There will be paralysis below the cut-position.
(any 2) @(1) × 2
Essay (p. 16-36)
18 HKDSE Biology Practice Paper 2012 IB Q12
Positive phototropic response of the shoot (1) enables the leaves to be brought into
positions that enable them to receive maximum sunlight for photosynthesis (1)
OR
Negative phototropic response of the root (1) enables the root to grow deep into the soil for
firm anchorage / obtain water from deeper ground, (1)
Any 1 set, Max. (2)
Nature:
Tropic response is a directional growth response of some parts of the plant to a
unidirectional stimulus (1)
whereas reflex action is a stereotyped response to a stimulus. (1)
[i.e. growth response vs non-growth response; unidirectional stimulus vs stimulus not
necessarily be unidirectional]
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 Oxford University Press 2014
New Senior Secondary Mastering Biology (Second Edition)
Book 2
Process:
Tropic response is mediated by auxins / chemical substances while reflex action is
mediated by nerve impulses which are electrochemical in nature. (1)
The same stimulus can cause tropic responses in different parts of the plants (e.g. root tips
and shoot tips), but the response in reflex action is localised. (1)
The response in tropism is slow whereas the reflex response is always fast. (1)
Different effectors (e.g. shoot tips / root tips) can show different responses (positive or
negative) to the same stimulus (e.g. unidirectional light). However, the effectors in the
reflex action always give the same response. (1)
Nature + Process Max. (5)
Communication (3)
Mark award for communication:
Clarity of expression and relevance to the
Mark
question
Answers are easy to understand. They are
fluent showing good command of
3
language.
There is no or little irrelevant material.
Language used is understandable but there
is some inappropriate use of words.
2
A little relevant material is included, but
does not mar the overall answer.
Markers have to spend some time and
effort on understanding the answer(s).
1
Irrelevant material obscures some minor
ideas.
Language used is incomprehensible.
0
Irrelevant material buries the major ideas
required by the question.
Logical and systematic presentation
Answers are well structured
showing coherence of thought and
organisation of ideas.
Answers are organised, but there is
some repetition of ideas.
Answers are a bit disorganised, but
paragraphing is evident.
Repetition is noticeable.
Ideas are not coherent and
systematic. Candidates show no
attempt to organise thoughts.
Reading to learn (p. 16-37)
1
2
3
The chicken would have bled to death due to a lack of oxygen carried by the blood. (1)
The medulla oblongata is the reflex centre for many reflex actions in the head. (1)
It also controls involuntary actions such as breathing and heart beat. (1)
No (1)
It is because the chicken had lost its cerebrum, which is the site for thinking and making
decisions. (1)
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 Oxford University Press 2014