To which body part pituitary gland is attached?
Pituitary gland is attached to brain.
Why endocrine gland are also referred to as ductless glands?
Endocrine glans are referred to as ductless glands because they release the hormones directly into the blood stream. They do not have any ducts for their secretion.
Name the hormones which control metamorphosis in insects and frog.
Thyroxine hormone controls metamorphosis in frogs.
Insect hormones control insect metamorphosis.