Question

Write one example each of the following tropic movements : 

(i) Positive phototropism 

(ii) Negative phototropism 

(iii) Positive geotropism 

(iv) Negative geotropism 

(v) Hydrotropism 

(vi) Chemotropism

Answer 1

(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.