State whether the following statement is true or false: Blood pressure,salivation,and vomiting are controlled by the cerebrum.

Plant roots grow towards water. What type of tropism is this?

$(a)$ Define hormone. Write four characteristics of hormones in humans.
$(b)$ Name the disorder caused by the following situations:
$(i)$ Under secretion of growth hormone
$(ii)$ Over secretion of growth hormone
$(iii)$ Under secretion of insulin
$(iv)$ Deficiency of iodine

State the function of: $(i)$ gustatory receptors,and $(ii)$ olfactory receptors.

State whether the following statement is true or false: The pituitary gland secretes growth hormone.

Which endocrine gland controls the functioning of most other endocrine glands?