Answer the following:
$(a)$ Which hormone is responsible for the changes noticed in females at puberty?
$(b)$ Dwarfism results due to deficiency of which hormone?
$(c)$ Blood sugar level rises due to deficiency of which hormone?
$(d)$ Iodine is necessary for the synthesis of which hormone?

(N/A) Oestrogen is the hormone responsible for the development of secondary sexual characteristics in females at puberty.
$(b)$ Dwarfism is caused by the deficiency of Growth Hormone $(GH)$,which is secreted by the pituitary gland.
$(c)$ Blood sugar level rises (hyperglycemia) due to the deficiency of Insulin,which is secreted by the pancreas.
$(d)$ Iodine is essential for the synthesis of Thyroxin,which is produced by the thyroid gland.