Uday 2025
PRACTICE SHEET
(BIOLOGY)
Chapter: Mineral Nutrition
Multiple Choice Answer Type Questions 8. Thiobacillus is a group of bacteria helpful in
carrying out:
1. Chlorosis is caused due to deficiency of:
(1) nitrogen fixation.
(1) Mg (2) Ca
(2) chemoautotrophic fixation.
(3) B (4) Cl
(3) nitrification.
(4) denitrification.
2. The amino acid having S in its composition is:
(1) methionine (2) cysteine
Assertion and Reason Answer Type Questions:
(3) both (1) and (2) (4) glutamic acid
9. Direction: Each of these questions contains two
3. Manganese is required in: statements Assertion (A) and Reason (R). Each of
(1) plant cell wall formation. these questions also has four alternative choices,
(2) photolysis of water during photosynthesis. any one of which is the correct answer. You have to
(3) chlorophyll synthesis. select one of the codes (1), (2), (3) and (4) given
(4) nucleic acid synthesis. below.
Assertion (A): Manganese is an activator of enzyme
4. For its action, nitrogenase requires: nitrite reductase.
(1) Mn2+ Reason (R): Manganese deficient cells prefer
(2) super oxygen radicals ammonia over nitrate.
(3) high input of energy (1) Both Assertion (A) and Reason (R) are the
(4) light true, and Reason (R) is a correct explanation
of Assertion (A).
5. Select the mismatch: (2) Both Assertion (A) and Reason (R) are the
(1) Rhodospirillum – Mycorrhiza true, but Reason (R) is not a correct
(2) Anabaena – Nitrogen fixer explanation of Assertion (A).
(3) Rhizobium – Alfalfa (3) Assertion (A) is true, but Reason (R) is false.
(4) Frankia – Alnus (4) Assertion (A) is false, but Reason (R) is true.
6. In which of the following forms is iron absorbed by
Very Short Answer Type Questions
plants?
(1) Ferric 10. Which is the common nitrogen-fixer in paddy
(2) Ferrous fields?
(3) Free element
(4) Both (1) and (2) 11 Which element is related to auxin biosynthesis?
7. Which of the following elements is responsible for 12. Define denitrification.
maintaining turgor in cells?
(1) Magnesium (2) Sodium 13. How many H+ and ATP are required for synthesis
(3) Potassium (4) Calcium of one NH3 molecule?
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Short Answer Type Questions of a great significance and importance to agriculture
and horticulture.
14. How do entities in a mutualistic association benefit
The kind of deficiency symptoms shown in plants
from each other as seen in mycorrhiza?
include chlorosis, necrosis, stunted plant growth,
premature fall of leaves and buds, and inhibition of
15. Differentiate between macronutrients and
cell division. Chlorosis is the loss of chlorophyll
micronutrients.
leading to yellowing in leaves. This symptom is
caused by the deficiency of elements N, K, Mg, S,
16. Mention symptoms of any four mineral deficiencies
Fe, Mn, Zn and Mo. Likewise, necrosis, or death of
in plants.
tissue, particularly leaf tissue, is due to the
deficiency of Ca, Mg, Cu, K. Lack or low level of
Long Answer Type Questions N, K, S, Mo causes an inhibition of cell division.
17. What will be beneficial to plants if they are supplied Some elements like N, S, Mo delay flowering if
with excess nutrients? If no, why and if yes, how? their concentration in plants is low.
The deficiency of any element can cause multiple
symptoms and that the same symptoms may be
Case Based Study Answer Type Questions caused by the deficiency of one of several different
18. Read the following and answer any four elements.
questions.
The concentration of the essential element below I. Destruction of chlorophyll pigment molecule results
which plant growth is retarded is termed as critical into yellowing in leaves, such condition is termed
concentration. The element is said to be deficient as:
when present below the critical concentration. Since (1) necrosis (2) wilting of leaves
each element has one or more specific structural or (3) chlorosis (4) senescence
functional role in plants, in the absence of any
particular element, plants show certain II. When the concentration of the essential element
morphological changes. These morphological goes down to the low level, which result abnormal
changes are indicative of certain element and stunted plant growth is referred as:
deficiencies and are called deficiency symptoms. (1) deficiency concentration
The deficiency symptoms vary from element to (2) critical concentration
element and they disappear when the deficient (3) extreme concentration
mineral nutrient is provided to the plant. However, (4) ample concentration
if deprivation continues, it may eventually lead to
the death of the plant. The deficiency symptoms III. What indicate the elemental deficiency?
tend to appear first in the older tissues. For example,
the deficiency symptoms of nitrogen, potassium and IV. Name the condition in which tissue of plant became
magnesium are visible first in the senescent leaves. dead due to elemental deficiency.
The deficiency symptoms tend to appear first in the
young tissues whenever the elements are relatively V. What if essential elements critical concentration
immobile and are not transported out of the mature continues for long time?
organs. The aspect of mineral nutrition of plants is
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Answer Key
1. (1) 6. (1)
2. (3) 7. (3)
3. (2) 8. (4)
4. (3) 9. (1)
5. (1) 18. I-(3), II-(2)
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Hints & Solutions
Multiple Choice Answer Type Questions citrate, and then transported in the metaxylem to
the other parts of the plant.
1. (1)
Chlorosis is a condition in which the leaves
7. (3)
produce an insufficient amount of chlorophyll. It
Potassium (K+) is responsible for maintaining
causes the yellowing of leaves. Magnesium is the
turgor in cells. It is one of the essential
main component of chlorophyll, so its deficiency
macronutrients required by plants for their growth
causes insufficient production of leaves.
and development. Potassium plays a significant
role in regulating the osmotic pressure of cells,
2. (3)
which is critical for maintaining turgor.
Methionine and cysteine are the two amino acids
which contain sulphur in its side chain.
8. (4)
Thiobacillus denitrificans is chemolithoautotrophic
3. (2)
bacteria that denitrifies nitrate during oxidation of
Manganese is required in the photolysis of water
FeSx compounds.
during photosynthesis. During photosynthesis after
the water get split after assimilation of carbon
Assertion and Reason Answer Type Questions:
dioxide manganese activates fat forming enzymes
which function in the formation of riboflavin, 9. (1)
ascorbic acid, and carotene which works as Both Assertion (A) and Reason (R) are the true, and
electron transport during photosynthesis. Reason (R) is a correct explanation of Assertion (A).
4. (3) Very Short Answer Type Questions
Nitrogenase enzyme is present in prokaryotic
nitrogen fixers. The enzyme nitrogenase requires a 10. Oscillatoria is the common nitrogen-fixer in paddy
high input of energy to carry out biological fields.
nitrogen fixation. This can be illustrated by the
following equation. 11. Zinc element is related to auxin biosynthesis.
NO3− + NAD(P)H + H+ ⎯⎯⎯⎯⎯⎯ FAD/FMN →
nitrate reductase
12. The process by which some amount of nitrate
NO−2 + H2O + NADP+ present in the soil is also reduced to nitrogen (N2)
is called denitrification.
5. (1) NO3– → NO2– → N2
Mycorrhiza is the association of the fungus with The soil bacteria involved in this process are called
the root of the vascular host plant. It increases the denitrifying bacteria, e.g., Pseudomonas and
water and nutrition absorption capacity of the Thiobacillus.
plant. Rhodospirillum-mycorrhiza (the association
of the fungus with the root of the vascular host 13. 4H+ and 8 ATP are required for synthesis of one
plant). It increases the water and nutrition NH3 molecule.
absorption capacity of the plant. Rhodospirillum is
a facultative anaerobe. It is a nitrogen fixer which
Short Answer Type Questions
helps in the conversion of atmospheric nitrogen to
ammonia. It is not associated with roots of the 14. Mycorrhiza is a symbiotic association between the
vascular plant as mycorrhiza. roots of vascular plants and a fungus. This
association provides the fungus with a constant
6. (1) supply of carbohydrates. Plants in return procure the
Fe2+ (ferrous) form is relatively soluble but is benefit of the mycelium of the fungus which
readily oxidized to Fe3+ (ferric) at the junction of promotes its absorptive capacity of minerals and
the protoxylem and the metaxylem, chelated by water provided the large surface area of mycelium.
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15. Differences between macronutrients and dry weight of tissue by 10%. However, critical
micronutrients: concentration differs for various micronutrients
Macronutrients Micronutrients and different plants. For instance, beyond 600µ is
toxic for soybean and beyond 5300µ for
(i) These are present in These are present in
plant tissues in larger plant tissues in sunflowers. These toxic effects can be either due to
concentrations and relatively smaller interference in the absorption and functioning of
are known as major concentrations and nutrients or due to the excess of the micronutrient.
elements. are thus known as Example Toxicity in manganese can be due to:
trace elements. • A decrease in the uptake of iron and
(ii) Their concentration in Their Concentration magnesium.
plant tissues is 1mg or in plant tissues is • Hindrance of calcium translocation into shoot
more per gram of dry less than 1mg per apex.
matter of plant. gram of dry matter
of plant. • Hindrance of binding of magnesium to
specific enzymes.
(iii) These do not have any These produce toxic
toxic effect if present effects if present m
in slight excess. slight excess. Case Based Study Answer Type Questions
(iv) These act as structural There are mostly 18. I-(3), II-(2)
constituents of cell involved in the
organs and reserve functioning of III. In the absence of any element, plants show certain
food materials or enzymes, either by morphological changes. These morphological
functional acting as cofactor or changes are an indication of certain element
biomolecules. activators of deficiencies, these morphological and anatomical
enzymes changes occurred in plant are called deficiency
symptoms.
16. (a) Chlorosis-Non-development or loss of IV. Necrosis is a condition in which plant tissues
chlorophyll that leads to yellowing the entire become dead due to elemental deficiency,
leaf or part of it is termed chlorosis. particularly leaf tissue, is due to the deficiency of
(b) Mottling-It is the appearance of patches of Ca, Mg, Cu, and K.
green and non-green areas on leaves. V. Each essential element has one or more specific
(c) Necrosis-It is the localized death of tissue of structural or functional role in plants, in the
the leaf. absence of any element it results in certain
(d) Curling- It is caused due to unequal growth of morphological changes. These morphological
the leaf. changes are indicative of certain element
deficiencies and are called deficiency symptoms.
The deficiency symptoms vary from element to
Long Answer Type Questions
element. When essential elements deprivation
17. No, it is not beneficial as higher doses of continues for long time, it may eventually lead to
micronutrients may become toxic. Toxic the death of the plant.
concentration is any concentration that reduces the
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