What is meant by stimulus and reaction?
Stimulus is the change in the environment or environmental factors to to which the organism can respond or react. Theresponse shown by organisms towards or awaya stimulus is called reaction.
What are disorders caused due to the hyposecretion and hypersecretion of the thyroxine hormone?
Hyposecretion of the thyroxine hormone cause simple goiters, the thyroid gland enlarges and become visible as a swelling of neck.
Hypersecretion of thyroxine hormone cause roughness on puffiness of the skin, falling of hairs, obesity, imbalance, digestive disorders, loss of weight and so on.