Mineral Nutrition — Page 3 | NEET Biology

Q21

The major role of minor elements inside living organisms is to act as

A binder of cell structure

B co-factors of enzymes

C building blocks of important amino acids

D constituent of hormones

Correct Answer

Option B

Solution

(b) Micronutrients mainly act as cofactors of enzymes (e.g., Zn activates carboxylases).

Q22

The most abundant element present in the plants is

A Carbon

B Nitrogen

C Manganese

D Iron

Correct Answer

Option A

Solution

(a) Carbon makes up ~45,000 mg/g of plant dry weight — the most abundant element.

Q23

Which one of the following elements is not an essential micronutrient for plant growth?

A Zn

B Cu

C Ca

D Mn

Correct Answer

Option C

Solution

(c) Ca is a macronutrient; Zn, Cu and Mn are micronutrients.

Q24

A plant requires magnesium for

A protein synthesis

B chlorophyll synthesis

C cell wall development

D holding cells together.

Correct Answer

Option B

Solution

(b) Magnesium is the central metal atom in chlorophyll molecule.

Q25

Manganese is required in:

A plant cell wall formation

B photolysis of water during photosynthesis

C chlorophyll synthesis

D nucleic acid synthesis

Correct Answer

Option B

Solution

(b) Manganese is essential for photolysis (splitting) of water in PSII.

Q26

Which one of the following is not a micronutrient?

A Molybdenum

B Magnesium

C Zinc

D Boron

Correct Answer

Option B

Solution

(b) Magnesium is a macronutrient; Fe, Cu, B, Mo, Mn, Cl, Ni are micronutrients.

Q27

Which one of the following is essential for photolysis of water?

A Manganese

B Zinc

C Copper

D Boron

Correct Answer

Option A

Solution

(a) Manganese ions in OEC (Oxygen Evolving Complex) of PSII catalyse photolysis of water.

Q28

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

Option C

Solution

(c) Cadmium is not an essential element; it is toxic to plants.

Q29

Which one of the following elements in plants is not remobilised?

A Phosphorus

B Calcium

C Potassium

D Sulphur

Correct Answer

Option B

Solution

(b) Calcium is not remobilised from older leaves to younger tissues.

Q30

Which of the following can fix atmospheric nitrogen?

A Albugo

B Cystopus

C Saprolegnia

D Anabaena

Correct Answer

Option D

Solution

(d) Anabaena is a nitrogen-fixing cyanobacterium.