Question

Read the information carefully and answer the following question

Gland W releases a hormone X in human. The hormone X is also required in frog for their

development from tadpole to adult frog. The hormone X requires nutrient Y for secretion. If it

is deficient in our diet then it causes disease Z.

a) Identify W, X, Y and Z

b) Give one source of Y.

c) Give two effects of disease Z

d) Mention the function of hormone X​

Answer 1

Gland THYROID releases a hormone THYROXINE in human. The hormone THYROXINE is also required in frog for their development from tadpole to adult frog. The hormone THYROXINE requires nutrient IODINE for secretion. If it is deficient in our diet then it causes disease SIMPLE GOITRE.

a.

• W is thyroid gland.
• X is thyroxine hormone.
• Y is iodine.
• Z is simple goitre.

b. The sources of iodine are iodised salt, some fishes and dairy products like milk, curd.

c. The hyposecretion of thyroxine causes goitre. The iodine deficiency result in less production of thyroxine. It results in the swelling of thyroid gland in the nech region. Rarely the person may develop difficulty in breathing.

d.

• Thyroxine helps in development of brain and neural tissues in the foetus.

• Thyroxine maintains the BMR, basal metabolic rate of the body.

• It has calorigenic effect.