The growth of pollen tubes towards ovules is due to:

Which of the following statements are true about the brain?
$(i)$ The main thinking part of the brain is the hindbrain.
$(ii)$ Centres of hearing,smell,memory,sight,etc.,are located in the forebrain.
$(iii)$ Involuntary actions like salivation,vomiting,and blood pressure are controlled by the medulla in the hindbrain.
$(iv)$ The cerebellum does not control posture and balance of the body.

Which of the following statements about the transmission of a nerve impulse is incorrect?

Which of the following is not an involuntary action?

Tendrils encircle or coil around the object in contact with it. Elaborate.

Electrical impulse travels in a neuron from :