Question

Which of the following movements can be seen in fungal hyphae?

• A. Chemotactic
• B. Chemotropic
• C. Thigmotropic
• D. None of the above

Answer 1

The correct option is B Chemotropic

Paratonic growth movements are the induced movements of growth caused by external stimuli such as gravity, light, water or contact. The movements show a directional relation to the stimulus. The stimuli are effective in causing growth movements only when they are unidirectional. Such movements are generally known as tropic movements and the phenomenon is referred to as tropism.

Based on the nature of stimulus, tropisms may be of various types-
(A) Geotropism- external stimulus provided by gravity.
(B) Phototropism- external stimulus provided by light.
(C) Hydrotropism- external stimulus provided by water.
(D) Chemotropism- external stimulus provided by chemicals.

Fungal hyphae grow towards the sugars. This is chemotropism. It is different from chemotactism in which entire body of organism moves towards or away from a particular chemical. The chemotactic movement does not involve growth.
(E) Thigmotropism- external stimulus provided by touch or contact.

Hence the correct option is B.