Question

Name the organ/part of a plant which shows:

1. Positive hydrotropism
2. Positive phototropism
3. Negative geotropism
4. Positive chemotropism

Answer 1

1. Positive Hydrotropism:
The organ that shows positive hydrotropism is the roots of the plant. Roots grow towards the source of water in response to moisture gradients in the soil.

2. Positive Phototropism:
The organ that shows positive phototropism is the stem of the plant. The stem grows towards light, helping the plant maximize its exposure to sunlight for photosynthesis.

3. Negative Geotropism:
The organ that shows negative geotropism is the stem of the plant. The stem grows upward, away from the gravitational pull of the Earth.

4. Positive Chemotropism:
The organ that shows positive chemotropism is the pollen tube in plants. The pollen tube grows towards the ovule in response to chemical signals released by the ovule for fertilization.