Deficiency symptoms of nitrogen and potassium are visible first in:

1. Senescent leaves

2. Young leaves

3. Roots

4. Buds

The most abundant intracellular cation is:
1. Ca²⁺
2. H⁺
3. K⁺
4. Na⁺

Best defined function of manganese in green plants is :

1. Photolysis of water

2. Calvin cycle

3. Nitrogen fixation

4. Water absorption

Which one of the following is a wrong statement?

An element playing important role in nitrogen fixation is:

1. molybdenum

2. copper

3. manganese

4. zinc

The function of leghemoglobin in the root nodules of legumes is:
1. oxygen removal
2. nodule differentiation
3. expression of nif gene
4. inhibition of nitrogenase activity

Which one of the following is not a micronutrient?

1. Molybdenum

2. Magnesium

3. Zinc

4. Boron

The free-living, anaerobic nitrogen-fixer is:

1. Beijerinckia

2. Rhodospirillum

3. Rhizobium

4. Azotobacter

Manganese is required in:
1. nucleic acid synthesis
2. plant cell wall formation
3. photolysis of water during photosynthesis
4. chlorophyll synthesis