Question

(a) Define geotropism. Give one example of geotropism. 

(b) What is meant by ‘positive geotropism’ and ‘negative geotropism ? Give one example of each type. Draw a labelled diagram to illustrate your answer indicating the plant part which shows positive geotropism and the plant part which shows negative geotropism. 

(c) Name one plant part which exhibits positive thigmotropism.

Answer 1

(a) The movement of plant part in response to gravity is called geotropism. Example – Roots grow towards gravity. 

(b) If the plant part moves towards the direction of gravity, it is called positive geotropism. 

Example – Roots. If the plant part moves against the direction of the gravity it is negative geotropism. Example – Stem

(c) Tendrils.