Plant and Animal Hormones (Science)
Points to Remember
· Auxins are produced at the tip of stems and roots from where they migrate to the zone of elongation.
· Cytokinins are the plant hormones that promote cell division or cytokinesis in plant cells.
· Gibberellins induce the formation of seedless fruit and parthenocarpic fruits.
· Abscisic acid is a growth inhibitor which regulates abscission and dormancy. It increases tolerance of plants to various kinds of stress.
· Ethylene is a gaseous plant hormone mainly concerned with maturation and ripening of fruits.
· The pituitary gland regulates and controls other endocrine glands and so is called as the “Master gland”.
· The hormones secreted by the thyroid gland are triiodothyronine (T3), and tetraiodothyronine or thyroxine (T4)
· The parathormone act on bone, kidney and intestine to maintain blood calcium levels.
· Pancreas secretes insulin and glucagon.
· They maintain blood glucose level.
· Adrenal cortex secrete coritsol and aldosterone and adrenal medulla secretes epinephrine and norepinephrine.
· The sex glands are of two types the testes and the ovaries which secrete testosterone and estrogens respectively.