Spinal cord originates from:

How is the timing and the amount of hormone secreted by a gland regulated? Explain with an example.

Which is the male sex hormone?

$(a)$ Name the part of the brain which controls:
$(i)$ voluntary actions,
$(ii)$ involuntary actions.
$(b)$ What is the significance of the peripheral nervous system? Name the components of this nervous system and distinguish between the origin of the two.

What is the correct direction of flow of electrical impulses?

The shape of guard cells changes due to change in the :