Mineral Nutrition

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Mineral Nutrition
135
Mineral Nutrition
1. Minerals absorbed by roots move to
the leaf through [1988]
(a) xylem
(b) phloem
(c) sieve tubes
(d) none of the above
Solution: (a)
Along with water, minerals move upwards
through the trachaery elements of xylem.
2. Phosphorous and nitrogen ions
generally get depleted in soil because
they usually occur as [1989]
(a) neutral ions
(b) negatively charged ions
(c) positively charged ions
(d) both positively and negatively charged
but disproportionate mixture
Solution: (d)
Phosphorus and nitrogen are essential
elements normally required in large
quantities by plants.
3. Which one is an essential mineral, not
constituent
of
any
enzyme
but
stimulates the activity of many enzymes
[1989]
(a) Zn
(b) Mn
(c) K
(d) Mg
Solution: (c)
Potassium is not a constituent of any
enzyme but is an activator of enzymes.
Potassium is an essential mineral and is
found in more amounts in actively dividing
cells such as of buds young leaves, root
tips, etc. It has some other roles like
involved in regulating stomated movement
and protein synthesis.
4. Mycorrhiza is a symbiotic relationship
between roots of higher plants and
[1995]
(a) virus
(b) fungi
(c) bacteria
(d) blue green algae
Solution: (b)
Symbiotic relationship between roots of
higher plants and fungi is called
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mycorrhiza, e.g. Pinus roots associated
with fungal hyphae.
5. The association between blue-green
algae and fungi occurs in [1995]
(a) lichens
(b) symbiosis
(c) cannibism
(d) mycorrhiza
Solution: (a)
In lichens, the association between an
algae and a fungus is considered to be a
symbiotic one. In this association, algae
provides food to fungi.
6. Which of the following can fix
atmospheric nitrogen? [1995]
(a) Albugo
(b) Cystopus
(c) Saprolegnia
(d) Anabaena
Solution: (d)
Anabaena is a nitrogen fixing blue-green
alga composed of barrel-shaped cells held
in a gelatinous matrix. So it can fix
atmospheric nitrogen.
7. Which one of the following is a
micronutrient for plants? [1996]
(a) Calcium
(b) Magnesium
(c) Manganese
(d) Nitrogen
Solution: (c)
Nutrients which are required in large
amounts and functioning of plant are
known as macronutrients eg. Ca, Mg, N.
Nutrients required in trace amounts are
known as micronutrients. Manganese is a
micronutrient for plants essential for
synthesis of chlorophyll. It is also required
for activation of enzymes of respiration and
nitrogen metabolism.
8. Which one of the following is not an
essential element for plants? [1996]
(a) Potassium
(b) Iron
(c) Iodine
(d) Zinc
Solution: (c)
Iodine is the only such element which is
an essential mineral for animals but is not
required by plants.
136
9. Which of the following is not caused
by deficiency of mineral nutrition?
[1997]
(a) Necrosis
(b) Chlorosis
(c) Etiolation
(d) Shortening of internodes
Solution: (c)
Etiolation is a plant response to stimuli.
When plant seeds are grown in insufficient
light, either in partial or complete absence
of light, the seedlings will have long, weak
stems, smaller and fewer leaves because of
longer internodes, and a pale yellow colour
(chlorosis). This is due to a lack of
chlorophyll. The plant‘s increase in height
helps it to reach a possible source of light
faster.
10. Which of the following is a free living
aerobic nonphotosynthetic
nitrogenfixer? [1997]
(a) Rhizobium
(b) Azotobacter
(c) Azospirillum
(d) Nostoc
Solution: (b)
Rhizobium is a symbiotic nitrogen fixer.
Azospirillum is a nitrogen fixing fungus and
Nostoc is anaerobic.
11. A pair of insectivorous plants is
[1999]
(a) Drosera and Rafflesia
(b) Nepenthes and Bladderwort
(c) Dionaea and Viscum
(d) Venus fly trap and Rafflesia
Solution: (b)
Insectivorous plants supplement the
supply of nitrogenous food by capturing
and digesting insects. Pitcher plant
(Nepenthes) and bladderwort (Utricularia)
are both insectivorous plants.
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12. The plants grown in magnesiumdeficient but urea sprayed soil would
show [2000]
(a) deep green foliage
(b) early flowering
(c) yellowing of leaves
(d) loss of pigments in petals
Solution: (c)
Deficiency
of
magnesium
produces
chlorosis due to breakdown of chlorophyll.
In botany, chlorosis is a condition in which
plant
foliage
produces
insufficient
chlorophyll. When this happens, leaves do
not have their normal green colour; they
may be pale green, yellow, or yellowwhite.
The affected plant has little or no ability to
manufacture carbohydrates and may die
unless the cause of its chlorophyll
insufficiency is treated. Specific nutrient
deficiencies (often aggravated by high pH)
produce chlorosis, which may be corrected
by
supplemental
feedings
of
iron,
magnesium or nitrogen compounds in
various combinations. Some pesticides,
particularly herbicides, may also cause
chlorosis, both to target weeds and
occasionally to the crop being treated.
13. Enzyme involved in nitrogen
assimilation [2001]
(a) nitrogenase
(b) nitrate reductase
(c) transferase
(d) transaminase
Solution: (a)
A molecule of N2 is changed to ammonia by
nitrogenase. Transaminase transfers amino
group from one substrate to another.
14. Passive absorption of minerals
depend on [2001]
(a) temperature
(b) temperature and metabolic inhibitor
(c) metabolic inhibitor
(d) humidity
Solution: (a)
Roots do not spend any energy on this type
of mineral absorption. So application of a
metallic inhibitor will not retard the
process.
15. Which aquatic fern
nitrogen fixation? [2001]
(a) Azolla
performs
137
(b) Nostoc
(c) Salvia
(d) Salvinia
Solution: (a)
Azolla performs nitrogen fixation through
its colonies of Anabaena azollae, which
have the capacity to fix atmospheric
nitrogen.
16. In plants inulin and raphides [2001]
(a) reserved food material
(b) wastes
(c) secretory material
(d) insect attracting material
Solution: (a)
Inulin and raphides crystals are reserve
materials
in
plants.
Inulin
is
a
polysaccharide (a polymer of fructose) and
is present in Compositae. Raphides are
bunches of needle like crystal of calcium
oxalate found in certain plant cells.
17. Choose the correct match [2002]
(a) Trapa, Dionaea, Drosera
(b) Nepenthes ,Utricularia, Vanda
(c) Utricularia, Drosera, Dionaea
(d) Dionaea, Trapa, Vanda
Solution: (c)
These are all insectivorous plants.
18. The major role of minor elements
inside living organisms is to act as
[2003]
(a) binder of cell structure
(b) co-factors of enzymes
(c) building blocks of important amino
acids
(d) constituent of hormones
Solution: (b)
Minor elements are those which are
required by plants in very small amount.
These elements have a significant role in
enzyme
activities
(zinc
activates
carboxylases, carbonic anhydrase and
various dehydrogenases).
19. Which one of the following mineral
elements plays an important role in
biological nitrogen fixation? [2003]
(a) Molybdenum
(b) Copper
(c) Manganese
(d) Zinc
Solution: (a)
Topicwise Solved Previous Year Qs
Molybdenum
is
a
component
of
nitrogenase and nitrate reductase involved
during N2 fixation. Copper is essential for
photosynthesis and respiration. Zinc is
involved in synthesis of auxin. Manganese
is activator of enzymes involved in nitrogen
metabolism.
20. The major portion of the dry weight
of plants comprises of [2003]
(a) Carbon, hydrogen and oxygen
(b) Nitrogen, phosphorus and potassium
(c) Calcium, magnesium and sulphur
(d) Carbon, nitrogen and hydrogen
Solution: (a)
The major portion of the dry weight of
plants comprises of Carbon, hydrogen and
oxygen.
21. Boron in green plants assists in
[2003]
(a) sugar transport
(b) activation of enzymes
(c) acting as enzyme cofactor
(d) photosynthesis
Solution: (a)
Manganese is an activator of enzymes.
Copper is essential for photosynthesis.
Molybdenum is a cofactor of enzymes.
Boron assists in sugar transport.
22. Grey spots of oat are caused by
deficiency of [2003]
(a) Fe
(b) Cu
(c) Zn
(d) Mn
Solution: (d)
Grey spots of oat are caused by deficiency
of Manganese.
23.
A
free
living
nitrogen-fixing
cyanobacterium which can also form
symbiotic association with the water
fern Azolla is [2004]
(a) Tolypothrix
(b) Chlorella
(c) Nostoc
(d) Anabaena
Solution: (d)
The freshwater fern Azolla harbours
Anabaena (a blue green alga) in its leaf
cavities. Chlorella is simply a green alga.
Nostoc is a free living cyanobacteria
138
involved in
Tolypothrix.
Topicwise Solved Previous Year Qs
N2
fixation
and
so
is
24. The deficiencies of micronutrients,
not only affects growth of plants but also
vital functions such as photosynthetic
and mitochondrial electron flow. Among
the list given below, which group of
three elements shall affect most, both
photosynthetic
and
mitochondrial
electron transport: [2005]
(a) Co, Ni, Mo
(b) Ca, K, Na
(c) Mn, Co, Ca
(d) Cu, Mn, Fe
Solution: (d)
Copper: Electron transfer (Cu+ Cu 2+)
Maintenance of carbohydrate/ nitrogen
balance,
chlorophyll
synthesis.
Iron:
Electron transport in photosynthesis and
respiration (Fe 2+ Fe 3+) development of
chloroplasts,
chlorophyll
and
other
pigments, protein synthesis. Manganese:
Metabolism and photolytic evolution of
oxygen. A plants require magnesium for
chlorophyll synthesis. All four rings bind
with metal atom magnesium (Mg++), which
remain present at the center of chlorophyll
molecule.
25. A plant requires magnesium for
[2007]
(a) protein synthesis
(b) chlorophyll synthesis
(c) cell wall development
(d) holding cells together.
Solution: (b)
26. Which one of the following elements
is not an essential micronutrient for
plant growth? [2007]
(a) Zn
(b) Cu
(c) Ca
(d) Mn
Solution: (c)
Essential micro elements are Fe, Mn, Zn,
B, Cu, Mo and essential macronutrionts
are C,H, N, P, S, Ca, K, Mg.
27. Nitrogen fixation in root nodules of
Alnus is brought about by: [2008]
(a) Bradyrhizobium
(b) Clostridium
(c) Frankia
(d) Azorhizobium
Solution: (c)
Nitrogen fixation in root nodules of Alnus
is brought about by Frankia. Frankia is a
symbiotic nitrogen fixing bacteria in root
nodules of several nonlegune plants like
Casuarina (Australian Pine), Myrica and
Alnus (Alder).
28. Manganese is required in: [2009]
(a) plant cell wall formation
(b)
photolysis
of
water
during
photosynthesis
(c) chlorophyll synthesis
(d) nucleic acid synthesis
Solution: (b)
Manganese is essential for many plant
functions. Some of them are: • The
assimilation
of
carbon
dioxide
in
photosynthesis. • Itisinvolved in the
HillReactionwhere water is split during
photosynthesis. • It aids in the synthesis of
chlorophyll and in nitrate assimilation. •
Manganese activates fat forming enzymes. •
It functions in the formation of riboflavin,
ascorbic acid, and carotene. • It functions
in
electron
transport
during
photosynthesis.
29. Which one of the following pairs is
wrongly matched? [2009]
(a) Alcohol - nitrogenase
(b) Fruit juice - pectinase
(c) Textile - amylase
(d) Detergents - lipase
Solution: (a)
Alcohol and nitrogenase pair is wrongly
matched. Ethanol produces alcohol.
30. Which of the following is a symbiotic
nitroger fixer? [2009]
(a) Azotobacter
(b) Frankia
(c) Azolla
(d) Glomus
Solution: (b)
Frankia is symbiotic nitrogen fixer in root
nodules of several non-legume plants like
Casurina and Alnus.
31. An element playing important role in
nitrogen fixation is: [2010]
(a) Molybdenum
139
(b) Copper
(c) Manganese
(d) Zinc
Solution: (a)
Molybdenum is a micronutrient that plays
an important role in nitrogen fixation. It is
a part of nitrate reductase enzyme that
helps in nitrogen fixation.
32. Which one of the following is not a
micronutrient? [2010]
(a) Molybdenum
(b) Magnesium
(c) Zinc
(d) Boron
Solution: (b)
Magnesium
is
a
macronutrient.
Micronutrients are essential elements that
are required by plants in small amount.
They include Fe, Cu, B, Mo, Mn, Cl, and Ni.
Macronutrients, on the other hand, are
those essential elements that are required
by plants in larger amount. The examples
include C, H, O, N, S, P, K, Ca and Mg.
33. Nitrifying bacteria: [2011]
(a) oxidize ammonia to nitrates
(b) convert free nitrogen to nitrogen
compounds
(c) convert proteins into ammonia
(d) reduce nitrates to free nitrogen
Solution: (a)
The nitrifying bacteria bring about
transformations of ammonia to nitrite and
of nitrite to nitrate.
34. A prokaryotic autotrophic nitrogen
fixing symboint is found in: [2011]
(a) Alnus
(b) Cycas
(c) Cicer
(d) Pisum
Solution: (b)
A prokaryotic autotrophic nitrogen fixing
symbiont is found in Cycas.
35. Which one of the following elements
in plants is not remobilised? [2011]
(a) Phosphorus
(b) Calcium
(c) Potassium
(d) Sulphur
Solution: (b)
Topicwise Solved Previous Year Qs
Calcium is not remobilized from the leaves
to the fruits, like potassium, phosphorus
and sulphur. It occurs abundantly in a
non-exchangeable form such as anorthite
(CaAl2Si2O8).
36. Nitrifying bacteria: [2011]
(a) oxidize ammonia to nitrates
(b) convert free nitrogen to nitrogen
compounds
(c) convert proteins into ammonia
(d) reduce nitrates to free nitrogen
Solution: (a)
The nitrifying bacteria bring about
transformations of ammonia to nitrite and
of nitrite to nitrate.
37. The function of leg haemoglobin in
the root nodules of legumes is: [2011]
(a) inhibition of nitrogenase activity
(b) oxygen removal
(c) nodule differentiation
(d) expression of nif gene
Solution: (b)
Leghaemoglobin is the haemoglobin like
red pigments found in root nodules of
legumes and reported to function as an
oxygen-carrying pigment in symbiotic
nitrogen fixation.
38. Which one of the following is not an
essential mineral element for plants
while the remaining three are? [2011M]
(a) Iron
(b) Manganese
(c) Cadmium
(d) Phosphorus
Solution: (c)
Cadmium is not an essential element for
plants. Phosphorus is macronutrient and
iron and manganese are micronutrients for
plants.
39. Which one of the following is
essential for photolysis of water?
[2011M]
(a) Manganese
(b) Zinc
(c) Copper
(d) Boron
Solution: (a)
Photolysis
is
catalysed
by
the
proteinbound inorganic complex containing
140
Topicwise Solved Previous Year Qs
manganese ions (oxygen evolving complex)
of photosystem II.
40. Best defined function of Manganese
in green plants is: [2012]
(a) Photolysis of water
(b) Calvin cycle
(c) Nitrogen fixation
(d) Water absorption
Solution: (a)
The best defined function of manganese is
in the splitting of water to liberate oxygen
during photosynthesis. It is absorbed in the
form of manganous ions (Mn2+). It activates
many enzymes involved in photosynthesis,
respiration and nitrogen metabolism.
41. Which one of the following
correctly matched? [2012]
(a) Passive transport of nutrients - ATP
(b) Apoplast - Plasmodesmata
(c) Potassium - Readily immobilisation
(d) Bakane of rice seedlings - F. Skoog
Solution: (c)
is
42. Which one of the following is wrong
statement
(a) Anabaena and Nostoc are capable of
fixing nitrogen in free living state also.
(b) Root nodule forming nitrogen fixerslive
as aerobes under free-living conditions.
(c) Phosphorus is a constituent of cell
membranes, certain nucleic acids and cell
proteins.
(d) Nitrosomonas and Nitrobacter a re
chemoautotrophs.
Solution: (c)
Phosphorus is a constituent of nucleic
acids both DNA and RNA but absent in cell
membranes and cell proteins.
43. For its activity, carboxypeptidase
requires [2012M]
(a) zinc
(b) iron
(c) niacin
(d) copper
Solution: (a)
Carboxypeptidase is an exopeptidase
enzyme secreted by the pancreas that acts
only on the peptide linkage of a terminal
amino acid containing a free carboxyl
group.
Zinc
is
a
cofactor
for
carboxypeptidase.
In
digestion
carboxypeptidase, requires zinc for its
protein degrading action.
44. Read the following four statements
(A-D). (A) Both, photophosphorylation
and oxidative phosphorylation involve
uphill transport of protons across the
membrane. (B) In dicot stems, a new
cambium originates from cells of
pericycle at the time of secondary
growth. (C) Stamens in flowers of
Gloriosa and Petunia are polyandrous.
(D) Symbiotic nitrogen-fixers occur in
freeliving state also in soil. How many of
the above statements are correct?
[2012M]
(a) Two
(b) Three
(c) Four
(d) One
Solution: (c)
All the four statements are correct.
45. For its action, nitrogenase requires
[2012M]
(a) Mn2+
(b) light
(c) high input of energy
(d) super oxygen radicals
Solution: (c)
Nitrogenases are enzymes used by some
organisms to fix atmospheric nitrogen gas.
It is the only known family of enzymes that
accomplish this process. Nitrogenase
requires high input of energy & anaerobic
condition.
46. The first stable product of fixation of
atmospheric nitrogen in leguminous
plants is: [NEET 2013]
(a) Ammonia
(b)
(c) Glutamate
(d)
Solution: (a)
141
Ammonia is first stable compound produce
in fixation of atmospheric nitrogen in
leguminous plant. A molecule of nitrogen is
change into two molecules of ammonia. It
requires 16 ATP, a source of electron donor
ferredoxin, hydrogen donor NADPH or
FMNH2 and dinitrogenase enzyme.
47. Which two distinct microbial
processes are responsible for the release
of fixed nitrogen as dinitrogen gas (N2)
to the atmosphere? [NEET Kar. 2013]
(a) Anaerobic ammonium oxidation, and
denitrification
(b) Aerobic nitrate oxidation, and nitrite
reduction
(c) Decomposition of organic nitrogen, and
conversion of dinitrogen to ammonium
compounds
(d) Enteric fermentation in cattle, and
nitrogen fixation by Rhizobium in root
nodules of legumes
Solution: (a)
In the global nitrogen cycle, bacterial
denitrification is recognised as important
process that converts fixed nitrogen to
atmospheric nitrogen gas, N2. in marine
nitrogen cycle, anaerobic oxidation of
ammonium coupled to nitrate reduction,
contributes substantially to N2–production
in marine sediments.
48. Which of the following elements is a
constituent of biotin? [NEET Kar. 2013]
(a) Sulphur
(b) Magnesium
(c) Calcium
(d) Phosphorus
Solution: (a)
Biotin, also known as vitamin H, is a
water-soluble B-vitamin. It is a coenzyme
for carboxylase enzymes, involved in the
synthesis of fatty acids, isoleucine, valine
and in gluconeogenesis. Sulphur is a
constituent of biotin.
Topicwise Solved Previous Year Qs

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