Which hormone acts as a growth inhibitor in plants?

$(a)$ Give the functions of cerebellum. (any two)
$(b)$ Name the components of central nervous system.

Write true or false for the statement: Insulin raises the sugar level in the blood.

$(a)$ 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.

$(a)$ How are the movement of leaves of touch-me-not and the growth of a stem towards light different?
$(b)$ What is chemotropism? Give one example.
$(c)$ What is tropism?

Which of the following plant hormones acts as a growth promoter?