iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which of the following mineral ion is not remobilized in plants?
A.
Potassium
B.
Calcium
C.
Nitrogen
D.
Phosphorus
Correct Answer: B
Explanation:
The correct answer is :
Option B : Calcium
Mineral remobilization is a process in which nutrients are transported from older tissues (like mature leaves) to newer ones (like young leaves or developing seeds). Most mineral ions like potassium, nitrogen, and phosphorus are remobilized in plants. However, calcium, once incorporated into plant tissue, generally remains immobile. Therefore, calcium is considered a mineral ion that is not remobilized in plants.
2023
Q2
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Match Column I with Column II.
Column - I
Column - II
(A)
Nitrococcus
(I)
Denitrification
(B)
Rhizobium
(II)
Conversion of ammonia to nitrite
(C)
Thiobacillus
(III)
Conversion of nitrite to nitrate
(D)
Nitrobacter
(IV)
Conversion of atmospheric nitrogen to ammonia
A.
(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
B.
(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
C.
(A)-(II), (B)-(IV), (C)-(I), (D)-(III)
D.
(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
Correct Answer: C
Explanation:
The correct option is :
Option C : (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
Explanation :
(A) Nitrococcus - (II) Conversion of ammonia to nitrite: Nitrococcus is a type of bacteria involved in the nitrification process, specifically, it converts ammonia into nitrite.
(B) Rhizobium - (IV) Conversion of atmospheric nitrogen to ammonia: Rhizobium is a type of bacteria found in soil that fix nitrogen after becoming established inside root nodules of legumes. They convert atmospheric nitrogen into ammonia, a process known as nitrogen fixation.
(C) Thiobacillus - (I) Denitrification: Thiobacillus is involved in denitrification, the process of reducing nitrates and nitrites to nitrogen gas and returning it to the atmosphere.
(D) Nitrobacter - (III) Conversion of nitrite to nitrate: Nitrobacter is a genus of bacteria that play an important role in the nitrogen cycle, where they convert nitrite to nitrate.
2023
Q3
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which micronutrient is required for splitting of water molecule during photosynthesis?
A.
Molybdenum
B.
Magnesium
C.
Copper
D.
Manganese
Correct Answer: D
Explanation:
Manganese plays a major role in the splitting of water to liberate oxygen during photosynthesis.
Copper is essential for the overall metabolism in plants.
Molybdenum is included in nitrogen metabolism.
Magnesium activates several enzymes involved in photosynthesis and respiration.
2023
Q4
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Match List I with List II:
List I
List II
(A)
Iron
(I)
Synthesis of auxin
(B)
Zinc
(II)
Component of nitrate reductase
(C)
Boron
(III)
Activator of catalase
(D)
Molybdenum
(IV)
Cell elongation and differentiation
Choose the correct answer from the options given below:
A.
A-II, B-III, C-IV, D-I
B.
A-III, B-I, C-IV, D-II
C.
A-II, B-IV, C-I, D-III
D.
A-III, B-II, C-I, D-IV
Correct Answer: B
Explanation:
A) Iron : It is involved in the synthesis of chlorophyll and is an activator of catalase.
B) Zinc : It is required for the synthesis of the plant growth hormone auxin.
C) Boron : It is essential for cell elongation and differentiation, as well as pollen germination.
D) Molybdenum : It is a component of nitrate reductase, an enzyme that reduces nitrate to nitrite in plants.
So, the correct matching is :
A-III, B-I, C-IV, D-II
2022
Q5
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which of the following protects nitrogenase inside the root nodule of a leguminous plant?
A.
Glutamate dehydrogenase
B.
Catalase
C.
leg haemoglobin
D.
Transaminase
Correct Answer: C
Explanation:
The enzyme nitrogenase functions under anaerobic conditions as it is highly sensitive to molecular
oxygen. In order to protect these enzymes, the nodules contain a red or pink-coloured pigment called
leg haemoglobin. It is an O2 scavenger.
2022
Q6
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Match List-I with List-II
List - I
List - II
(a)
Manganese
(i)
Activates the enzyme catalase
(b)
Magnesium
(ii)
Required for pollen germination
(c)
Boron
(iii)
Activates enzymes of respiration
(d)
Iron
(iv)
Functions in splitting of water during photosynthesis
Choose the correct answer from the options given below:
A.
(a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
B.
(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
C.
(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
D.
(a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)
Correct Answer: B
Explanation:
Manganese plays a major role in the splitting of water to liberate oxygen during photosynthesis.
Magnesium activates several enzymes involved in photosynthesis and respiration.
Boron is involved in pollen germination. Iron activates the catalase and some other enzymes.
2022
Q7
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following produces nitrogen fixing nodules on the roots of Alnus?
A.
Rhizobium
B.
Frankia
C.
Rhodospirillum
D.
Beijerinckia
Correct Answer: B
Explanation:
The microbe, Frankia, produces nitrogen fixing nodules on the roots of non-leguminous plants (e.g. Alnus)
2021
Q8
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Match Column - I with Column - II.
Column-I
Column-II
(a)
Nitrococcus
(i)
Denitrification
(b)
Rhizobium
(ii)
Conversion of ammonia to nitrite
(c)
Thiobacillus
(iii)
Conversion of nitrite to nitrate
(d)
Nitrobacter
(iv)
Conversion of atmospheric nitrogen to ammonia
Choose the correct answer from options given below.
A.
(a)
(b)
(c)
(d)
(iv)
(iii)
(ii)
(i)
B.
(a)
(b)
(c)
(d)
(ii)
(iv)
(i)
(iii)
C.
(a)
(b)
(c)
(d)
(i)
(ii)
(iii)
(iv)
D.
(a)
(b)
(c)
(d)
(iii)
(i)
(iv)
(ii)
Correct Answer: B
Explanation:
$\bullet$ Nitrogen fixation is conversion of atmospheric N2 to NH3 (ammonia). It is carried out by N2 fixers such as Rhizobium.
$\bullet$ NH3 is converted to NO$_2^ - $ (nitrite) by nitrifying bacteria such as Nitrococus.
$\bullet$ Then NO$_2^ - $ is converted to NO$_3^ - $ (nitrate) by nitrifying bacteria called Nitrobacter.
$\bullet$ Thiobacillus carries out denitrification, a process where NO$_2^ - $ / NO$_3^ - $ is converted to N2.
2020
Q9
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Match the following concerning essential elements and their functions in plants
(a) Iron (i) Photolysis of water
(b) Zinc (ii) Pollen germination
(c) Boron (iii) Required for chlorophyll biosynthesis
(d) Manganese (iv) IAA biosynthesis
Iron is essential for the formation of
chlorophyll. Zinc is needed for synthesis of auxin.
Boron plays a role in pollen grain germination.
Manganese is involved in the splitting of water to
liberate O2 during photosynthesis.
2020
Q10
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
The product(s) of reaction catalyzed by
nitrogenase in root nodules of leguminous
plants is/are
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which of the following elements is responsible
for maintaining turgor in cells?
A.
Sodium
B.
Calcium
C.
Magnesium
D.
Potassium
Correct Answer: D
Explanation:
Plants require potassium ions (K+
) for
protein synthesis and for the opening and
closing of stomata, which is regulated by
proton pumps to make surrounding guard
cells either turgid or flaccid.
2018
Q12
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
In which of the following forms is iron absorbed
by plants?
A.
Ferrous
B.
Both ferric and ferrous
C.
Ferric
D.
Free element
Correct Answer: C
Explanation:
Iron is absorbed by plants in the form of ferric
ions.
2018
Q13
AIIMS
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Azolla is used as a biofertiliser because it
A.
has association of mycorrhiza
B.
multiplies at faster rate to produce massive biomass
C.
has association of nitrogen-fixing Rhizobium
D.
has association of nitrogen-fixing cyanobacteria
Correct Answer: D
Explanation:
Azolla is a pteridophyte and it is used as a
biofertiliser because it has association with
nitrogen-fixing cyanobacteria called Anabaena
azollae.
2018
Q14
AIIMS
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Assertion Nitrogen-fixing bacteria of
legume root nodules survive in oxygen
depleted cells.
Reason Leghaemoglobin completely
removes oxygen from nodule cells.
A.
Both A and R are true and R is the correct explanation of A
B.
Both A and R are true, but R is not the correct explanation of A
C.
A is true, but R is false
D.
A and R are false
Correct Answer: B
Explanation:
Enzyme nitrogenase is sensitive to O$_2$ and
therefore, it is found in oxygen depleted cells. In
the cells of root nodules leghaemoglobin is
present and pigment is an oxygen scavenger.
Hence, it provides anaerobic condition to nitrogen
fixing bacteria.
2018
Q15
AIIMS
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Assertion Magnesium is important in photosynthesis and carbohydrate metabolism.
Reason $\mathrm{Mg}^{2+}$ is involved in the synthesis of nucleic acids.
A.
Both A and R are true and R is the correct explanation of A
B.
Both A and R are true, but R is not the correct explanation of A
C.
A is true, but R is false
D.
A and R are false
Correct Answer: B
Explanation:
Magnesium is constituent of chlorophyll
molecule, without which, the photosynthesis
would not occur. Many of the enzymes involved in carbohydrate metabolism require magnesium
as an activator. Magnesium is also an activator
for enzymes involved in the synthesis of nucleic
acids (DNA, RNA).
2016
Q16
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which is essential for the growth of root tip?
A.
Zn
B.
Fe
C.
Ca
D.
Mn
Correct Answer: C
Explanation:
Calcium (Ca) is necessary for the proper
growth and functioning of root tips and meristems.
2016
Q17
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
In which of the following all three are macronutrients?
A.
Molybdenum, magnesium, manganese
B.
Nitrogen, phosphorus, sulphur
C.
Boron, Zinc, manganese
D.
Iron, copper, molybdenum
Correct Answer: B
Explanation:
Nitrogen, phosphorus, potassium,
calcium, sulfur and magnesium are the
macronutrients.
2015
Q18
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
The oxygen evolved during photosynthesis, comes from water molecules. Which one of the following pairs of elements is involved in this reaction?
A.
Magnesium and Molybdenum
B.
Magnesium and Chlorine
C.
Manganese and chlorine
D.
Manganese and Potassium
Correct Answer: C
Explanation:
During photosynthesis photolysis of
water is induced by Mn++ and CI– ions.
2015
Q19
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by
A.
carotene
B.
cytochrome
C.
leghaemoglobin
D.
xanthophyll.
Correct Answer: C
Explanation:
Leghaemoglobin is a pinkish pigment
present in the root nodules of leguminous plants. It
acts as oxygen scavenger and prevents the inactivation
of nitrogenase enzyme by oxygen poisoning.
2015
Q20
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Minerals known to be required in large amounts for plant growth include
A.
potassium, phosphorus, selenium, boron
B.
magnesium, sulphur, iron, zinc
C.
phosphorus, potassium, sulphur, calcium
D.
calcium, magnesium, manganese, copper.
Correct Answer: C
Explanation:
Macroelements (macronutrients) are those
essential elements which are present in easily
detectable quantities, i.e., 1-10 mg per gram of dry
matter. Macroelements are usually involved in the
synthesis of organic molecules and development of
osmotic potential. They are nine in number — C, H,
O, N, P, K, S, Mg and Ca.
2014
Q21
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Deficiency symptoms of nitrogen and potassium are visible first in
A.
senescent leaves
B.
young leaves
C.
roots
D.
buds.
Correct Answer: A
Explanation:
The parts of the plants that show the
deficiency symptoms also depend on the
mobility of the element in the plant. For
element that are actively mobilised within
the plants and exported to young developing
tissues, the deficiency symptoms tend to
appear first in the older tissues. For example,
nitrogen, potassium and magnesium are
visible first in the senescent leaves.
2013
Q22
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Specialized cells for fixing atmospheric nitrogen in Nostoc are
A.
heterocysts
B.
hormogonia
C.
modules
D.
akinetes.
Correct Answer: A
Explanation:
Certain species of cyanobacteria (Nostoc)
possess some special cells called heterocysts which
occur in terminal, basal and intercalary positions.
Heterocysts are yellowish in colour and contents are
homogenous. Heterocysts are now known as sites of
nitrogen fixation. Atmospheric nitrogen is made
available in the form of ammonia by cyanobacteria.
2013
Q23
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which two distinct microbial processes are responsible for the release of fixed nitrogen as dinitrogen gas (N2) to the atmosphere?
A.
Aerobic nitrate oxidation and nitrate reduction
B.
Decomposition of organic nitrogen and conversion of dinitrogen to ammonium compounds
C.
Enteric fermentation in cattle and nitrogen fixation by Rhizobium in root nodules of legumes
D.
Anaerobic ammonium oxidation and denitrification
Correct Answer: D
Explanation:
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.
2013
Q24
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which of the following elements is a constituent of biotin?
A.
Magnesium
B.
Calcium
C.
Phosphorus
D.
Sulphur
Correct Answer: D
Explanation:
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.
2013
Q25
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
The first stable product of fixaation of atmospheric nitrogen in leguminous plants is
A.
NO$_3^ - $
B.
glutamate
C.
NO$_2^ - $
D.
ammonia.
Correct Answer: D
Explanation:
The enzyme nitrogenase is a Mo- Fe protein
and catalyses the conversion of atmospheric nitrogen
to ammonia, the first stable product of nitrogen
fixation. Nitrogen fixation is the conversion of inert
atmospheric nitrogen or dinitrogen (N2
) into utilisable
compounds of nitrogen like nitrate, ammonia, amino
acids, etc.
There are two methods of nitrogen fixation
- abiological and biological. Biological nitrogen
fixation is performed by both free living and symbiotic
forms. Symbiotic nitrogen fixing organisms hand over
a part of their nitrogen to the host in return for shelter
and food. The nodule of leguminous plants contains
all the necessary biochemical components, such as
the enzyme nitrogenase and leghaemoglobin, for
nitrogen fixation.
2012
Q26
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
For its action, nitrogenase requires
A.
high input of energy
B.
light
C.
Mn2+
D.
super oxygen radicals.
Correct Answer: A
Explanation:
Nitrogenase enzyme is present in
prokaryotic nitrogen fixers. The enzyme nitrogenase
requires a high input of energy to carry out biological
nitrogen fixation. This can be illustrated by the
following equation.
2012
Q27
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following is correctly matched?
A.
Passive transport of nutrients $-$ ATP
B.
Apoplast $-$ Plasmodesmata
C.
Potassium $-$ Readily immobilisation
D.
Bakane of rice seedlings $-$ F. Skoog.
Correct Answer: C
Explanation:
Potassium immobilisation is the
conversion of water soluble potassium into
water insoluble form. Readily available
potassium constitutes about 1% of total
potassium available in soil, whereas slightly
soluble potassium accounts for about 98%.
2012
Q28
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Best defined function of manganese in green plants is
A.
photolysis of water
B.
Calvin cycle
C.
nitrogen fixation
D.
water absorption.
Correct Answer: A
Explanation:
The best defined function of manganese
is in the splitting of water to liberate oxygen
during photosynthesis. It is absorbed in the
form of manganese ions (Mn2+). It activates
many enzymes involved in photosynthesis,
respiration and nitrogen metabolism.
2011
Q29
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following is not an essential mineral element for plants while the remaining three are?
A.
Iron
B.
Manganese
C.
Cadmium
D.
Phosphorus
Correct Answer: C
Explanation:
Cadmium is not an essential element for
plants. Phosphorus is a macronutrient and
iron and manganese are micronutrients for
plants.
2011
Q30
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following elements in plants is not remobilised?
A.
Phosphorus
B.
Calcium
C.
Potassium
D.
Sulphur
Correct Answer: B
Explanation:
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).
2011
Q31
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following helps in absorption of phosphorus from soil by plants?
A.
Glomus
B.
Rhizobium
C.
Frankia
D.
Anabaena
Correct Answer: A
Explanation:
Glomus aggregatum is a mycorrhizal
fungus used as a soil inoculant in agriculture
and horticulture. Its purpose is to increase the
surface area of roots for nutrient absorption
like phosphorus.
2011
Q32
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Nitrifying bacteria
A.
oxidize ammonia to nitrates
B.
convert free nitrogen to nitrogen compounds
C.
convert proteins into ammonia
D.
reduce nitrates to free nitrogen.
Correct Answer: A
Explanation:
Nitrifying bacteria involves the oxidation
of ammonia to nitrates through nitrites called
nitrification. Nitrite bacteria (Nitrosomonas and
Nitrococcus) convert ammonia to nitrites whereas,
nitrate bacteria (Nitrobacter and Nitrocystis) convert
nitrite to soluble nitrates.
2011
Q33
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
The function of leghaemoglobin in the root nodules of legumes is
A.
inhibition of nitrogenase activity
B.
oxygen differentiation
C.
nodule differentiation
D.
expression of nif gene.
Correct Answer: B
Explanation:
The root nodule of legume contains enzyme
nitrogenase and leghaemoglobin. Nitrogenase
catalyses the conversion of atmospheric nitrogen to
ammonia. It is highly sensitive to the molecular
oxygen and requires anaerobic conditions. The
nodules have adaptations that ensure that the enzyme
is protected from oxygen. To protect these enzymes,
the nodule contains an oxygen scavenger called
leghaemoglobin.
2010
Q34
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Study the cycle shown below and select the option which gives correct words for all the four blanks A, B, C and D.
A.
A
B
C
D
Nitrification
Ammoni fication
Animals
Plants
B.
A
B
C
D
Denitrification
Ammoni fication
Plants
Animals
C.
A
B
C
D
Nitrification
Denitrification
Animals
Plants
D.
A
B
C
D
Denitrification
Nitrification
Plants
Animals
Correct Answer: B
Explanation:
A – Denitrification
B – Ammonification
C – Plants
D – Animals
2010
Q35
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen through the process of symbiotic nitrogen fixation. which one of the following statements is not correct during this process of nitrogen fixation?
A.
Leghaemoglobin scavenges oxygen and is pinkish in colour.
B.
Nodules act as sites for nitrogen fixation.
C.
The enzyme nitrogenase catalyses the conversion of atmospheric N2 to NH3
D.
Nitrogenase is insensitive to oxygen.
Correct Answer: D
2010
Q36
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following is not a micronutrient?
A.
Molybdenum
B.
Magnesium
C.
Zinc
D.
Boron
Correct Answer: B
Explanation:
Magnesium is a macronutrient.
Micronutrients are essential elements that
are required by plants in small amounts.
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 amounts. The examples include C,
H, O, N, S, P, K, Ca and Mg.
2010
Q37
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
An element playing important role in nitrogen fixation is
A.
molybdenum
B.
copper
C.
manganese
D.
zinc.
Correct Answer: A
Explanation:
Molybdenum is a micronutrient which is
required in very minute amount by the plants. It is
responsible for nodulation in legumes. It is part of
nitrate reductase enzyme which helps in nitrogen
fixation.
2009
Q38
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Manganese is required in
A.
plant cell wall formation
B.
photolysis of water during photosynthesis
C.
chlorophyll synthesis
D.
nucleic acid synthesis.
Correct Answer: B
Explanation:
Manganese (Mn2+) is used for photolysis of
water to produce oxygen and electrons during light
reaction of photosynthesis. It is the phenomenon of
breaking up of water into hydrogen and oxygen in
the illuminated chloroplast. It acts as an essential
cofactor.
2007
Q39
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
A plant requires magnesium for
A.
protein synthesis
B.
chlorophyll synthesis
C.
cell wall development
D.
holding cells together.
Correct Answer: B
Explanation:
Magnesium is an important constituent of
chlorophyll, found in all green plants and essential
for photosynthesis. The chlorophyll molecule has a
tetrapyrolic or porphyrin head and a phytol tail. Mg
atom is present in the centre of porphyrin head. It is
like tennis racket.
2007
Q40
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which one of the following elements is not an essential micronutrient for plant growth?
A.
Zn
B.
Cu
C.
Ca
D.
Mn
Correct Answer: C
Explanation:
Essential micro elements are Fe, Mn, Zn,
B, Cu, Mo and essential macronutrionts are
C,H, N, P, S, Ca, K, Mg.
2006
Q41
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Sulphur is an important nutrient for optimum growth and productivity in
A.
oilseed crops
B.
pulse crops
C.
cereals
D.
fibre crops.
Correct Answer: A
Explanation:
Sulphur is present in all the cells of the body
in association with proteins made of sulphur
containing amino acids, viz., cystine, cysteine and
methionine. Members of Cruciferae and animal
proteins are rich sources of sulphur; other vegetable
proteins (e.g., pulses) have only little sulphur. Plants
absorb sulphur from soil in the form of sulphate ions
(SO4
– –).
It is a constituent of ferredoxin and some of
the lipids present in chloroplasts. Pungent odour of
mustard, cabbage, turnip, etc. of Family Brassicaceae
is due to the presence of sulphur containing oils.
Application of 40 kg/ha to oilseed based cropping
system is found to increase the yield, oil and protein
content of the seeds.
2005
Q42
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
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?
A.
Co, Ni, Mo
B.
Ca, K, Na
C.
Mn, Co, Ca
D.
Cu, Mn, Fe
Correct Answer: D
Explanation:
Iron is mainly available in the ferrous form
and it is absorbed in the ferric form, also. It is a part
of catalases, peroxidases, cytochromes, etc. and plays
a role in electron transport system in photosynthesis.
Manganese is absorbed by the plants when it is in the
bivalent form. Manganese participates in the
photolysis of water in pigment system II during
photosynthesis and thus it helps in the electron
transport from water to chlorophyll.
Copper is
absorbed on the clay particles as divalent cations, from
where it can be absorbed by the plants by exchange
mechanism. It is constituent of plastocyanin which
takes part in electron transport during photosynthetic
phosphorylation.
2004
Q43
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
If by radiation all nitrogenase enzyme are inactivated, then there will be no
A.
fixation of nitrogen in legumes
B.
fixation of atmospheric nitrogen
C.
conversion from nitrate to nitrite in legumes
D.
conversion from ammonium to nitrate in soil.
Correct Answer: A
Explanation:
Nitrogenase is an enzyme involved in
biological nitrogen fixation. Enzyme nitrate
reductase is involved in conversion of nitrate
to nitrite. Conversion of ammonia to nitrate
is carried out by Nitrosomonas and Nitrobacter.
2003
Q44
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Gray spots of oat are caused by deficiency of
A.
Cu
B.
Zn
C.
Mn
D.
Fe
Correct Answer: C
Explanation:
Gray spot diseases of oat is caused due to
deficiency of manganese. Its symptoms include
greyish - brown elongated specks and streaks, empty
panicles, interveinal chlorosis on stem and leaves. The
symptoms that occur only on leaves are irregular,
greyish brown lesions which coalesce and bring about
collapse of leaf. This is called grey speck symptom.
2003
Q45
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Boron in green plants assists in
A.
activation of enzymes
B.
acting as enzyme co-factor
C.
photossynthesis
D.
sugar transport.
Correct Answer: D
Explanation:
Manganese is an activator of enzymes.
Copper is essential for photosynthesis.
Molybdenum is a cofactor of enzymes.
Boron assists in sugar transport.
2002
Q46
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Choose the correct match.
Bladderwort, sundew, Venus flytrap
A.
Nepenthes, Dionea, Drosera
B.
Nepenthes, Utricularia, Vanda
C.
Uricularia, Drosera, Dionea
D.
Dionea, Trapa, Vanda.
Correct Answer: C
Explanation:
Bladderwort or Utricularia is a rootless free
floating insectivorous plant. Its stem is green and
bears green lobed or dissected leaves. Some lobes of
the leaves become modified into bladder like
structures for catching insects. Sundew or Drosera
is another insectivorous plant which has leaves that
are green and bear many glandular hairs or tentacles
having shining droplets to attract the insects and later
trap them.
Venus flytrap or Dionea is also an
insectivorous plant in which the leaf is modified into
two jaw like structures. Each jaw has long sensitive
hairs on its upper surface and also has many digestive
enzymes. These jaws interlock to trap the insect that
enters in it. Thus Utricularia, Drosera and Dionea
are all insectivorous plants.
2001
Q47
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Roots of which plant contains a red pigment which have affinity for oxygen?
A.
Carrot
B.
Soybean
C.
Mustard
D.
Radish
Correct Answer: B
Explanation:
Leghaemoglobin is a red respiratory pigment
found in the root nodules of leguminous plant if
Rhizobium is present. Soybean is a legume plant so it
contains leghaemoglobin in its root nodules.
2001
Q48
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Which aquatic fern performs nitrogen fixation?
A.
Azolla
B.
Nostoc
C.
Salvia
D.
Salvinia
Correct Answer: A
Explanation:
Azolla performs nitrogen fixation through
its colonies of Anabaena azollae, which have
the capacity to fix atmospheric nitrogen.
2000
Q49
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
When the plants are grown in magnesium deficient but urea rich soil, the symptoms expressed are
A.
yellowish leaves
B.
colourless petiole
C.
dark green leaves
D.
shoot apex die.
Correct Answer: A
Explanation:
Magnesium is important constituent of
chlorophyll, thus it is found in all green plants and is
essential for photosynthesis. It also helps in binding
of ribosomal particles where protein synthesis occurs.
It is also part of many enzymes of respiration. The
deficiency symptoms of magnesium includes
interveinal chlorosis in leaves and yellowing of leaves
starting from basal to younger ones.
2000
Q50
NEET
MCQ
iCON Education HYD, 79930 92826, 73309 7282610 Mar 2026
Plants take zinc in the form of
A.
ZnSO4
B.
Zn++
C.
ZnO
D.
Zn.
Correct Answer: B
Explanation:
Zinc is available to the plants for absorption
in the divalent form. The availability of soil decreases
when the pH of soil shifts towards alkaline side. Zinc
may form zinc phosphate in the soil which is insoluble
and in that case, it is not available to the plants. It is
essential for synthesis of tryptophan, amino acid
which forms IAA (Indole Acetic Acid). Its deficiency
causes chlorosis of older leaves.
