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

At the time of puberty,both boys and girls show many changes in their appearance. Name the hormones responsible for these changes.

$(a)$ Define reflex arc. Draw a flow chart showing the sequence of events which occur during sneezing.
$(b)$ List four plant hormones. Write one function of each.

How many lobes does the surface of the cerebral hemisphere possess?

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.
$(iv)$ Cerebellum does not control posture and balance of the body.

Explain how the human body responds when adrenaline is secreted into the blood.