Question

a) Do you agree with the statement - "All hormones are chemical signals"?Yes / No. Justify your answer.

b) Why is iodine a nutrient important to our body? [4 MARKS]

Answer 1

a) 2 Marks
b) 2 Marks

a) Yes, all hormones are chemical signals because they are highly active organic substances secreted in some parts of the body and circulated throughout the body with blood to alter the metabolic process of specific target cells in other parts of the body.

b) Iodine is important to our body because it is the active ingredient in the production of thyroxine. Insufficient secretion of thyroxine may lead to the following three conditions.

(i) Simple goitre (ii) Cretinism (iii) Myxoedema.
Oversecretion of thyroxine may also cause a kind of goitre, called exophthalmic goitre.