In a neuron,conversion of electrical signal to a chemical signal occurs at/in:

Illustrate with the help of a diagram,the effect of auxins in different parts of a plant.

The substance that triggers the fall of mature leaves and fruits from plants is due to

Which system facilitates the communication between the central nervous system and other parts of the body?

In which lobe of the cerebrum are the centers for temperature,smell,and touch located?

$(a)$ Name the diseases by which a person is likely to suffer due to the deficiency of:
$(i)$ Iodine
$(ii)$ Insulin
$(b)$ How are the timing and amount of hormone secretion regulated in the human system? Explain with an example.