Question

Define the following terms:

(i) Hypotropism

(ii) Geotropism

(iii) Chemotropism

Answer 1

(i) Hypotropism:

1. The directional growth movement occurring in plants in response to a directional water stimulus is called hydrotropism.
2. Roots of bend pants band grow towards the water or moisture source and exhibit hydrotropism.

(ii) Geotropism:

1. The directional growth movement exhibited by plants in response to gravity is called geotropism.
2. Roots grow in the direction of gravitational pull and exhibit geotropism.

(iii) Chemotropism:

1. Chemotropism is the directional growth movement in response to a chemical stimulus.
2. The pollen tube exhibits chemotropism when it grows towards the chemical secreted by the ovary during pollen tube germination.