Question

Explain in detail with 01 example of positive tropism and 01 example of negative
tropism for each of the following:-
a) Phototropism
b) Geotropism
c) Hydrotropism
d) Thigmotropism
e) Chemotropism

Answer 1

Answer:

(i) Positive phototropism: shoots growing towards light. (ii) Negative phototropism: roots growing away from light towards ground.

(iii) Positive geotropism: growth of roots towards earth due to the pull of the earth.

(iv) Negative geotropism: shoots growing away from the earth.

(v) Hydrotropism: roots growing towards the source of water.

(vi) Chemotropism: growth of pollen tubes towards the ovules.