The uptake of which of the following by a plant contributes maximum to its dry weight:
1. water and minerals through root hairs.
2. water and minerals through mycorrhizae.
3. carbon dioxide by leaves through stoma.
4. sugars in the root hairs.

Plant growing in absence of light will show increased:
1. uptake of minerals
2. uptake of water
3. elongation of internodes
4. ascent of sap

Carnivorous plants are almost entirely restricted to habitats like bogs where:

1. soil nutrients are extremely limiting, but where sunlight and water are readily available.

2. soil has very low nitrogen but other minerals are adequate and there is shortage of sunlight.

3. soil nutrients, sunlight and water are all in very limited supply.

4. soil nutrients are readily available, but where sunlight and water are extremely limiting.

Protein malnutrition is a serious problem in developing countries. If the essential amino acids in crop plants for human consumption can be increased, it can help to overcome this problem. The best method to produce such crop plants is by:
1. breeding for higher yield of deficient amino acids.
2. increasing the amount of NPK fertilizer used on fields.
3. creating mutants that do not form symbiotic relationship with microbes.
4. transferring nitrogen fixing genes to plants through genetic engineering.