The property of soil that is least conducive to plant growth would be:
1. a large percent of humus content
2. a large number of soil organisms
3. a compacted soil
4. a soil with high porosity

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.

What percentage of the dry weight of a plant is made up of organic molecules?
1. 10%
2. 23%
3. 72%
4. 96%

Assertion: High acidic soils can present problems for plant growth.
Reason: At low pH, aluminum ions toxicity becomes important.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Young seedlings frequently show mineral deficiency symptoms.
Reason: Their requirement is much lower than the requirements of older plant parts.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

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.

Phytoremediation is:
1. concentrating minerals in rhizosphere.
2. minimizing soil erosion in arid lands.
3. nitrogen fixation by symbiotic bacteria in root nodules.
4. removal of heavy metals from polluted sites.

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.

Assertion: Negatively charged ions in soils are more easily lost by leaching than positively charged ions.
Reason: Soil particles in most productive soils are positively charged.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.