Chapter 21, Problem 1E

Summary Introduction

Introduction :

In endocrinology, the permissive effect can be defined as where one hormone can work in the presence of another hormone. Permissiveness is a type of biochemical phenomenon, in which the presence of one hormone is necessary to activate another hormone for its full effects on a target cell.

Answer to Problem 1E

Correct answer :

Correct answer is option (d) Both a and c.

Explanation of Solution

Explanation/justification for the correct answer :

Option (a) effect of thyroid hormone on growth. The thyroid is a steroid hormone and it can bring out changes in the expression of certain genes. The thyroid hormone can promote the transcription of the gene involved in the production of the growth hormone. So, the secretion of the growth hormone cannot be done in the absence of the thyroid hormone. In this case, the thyroid hormone poses permissiveness for the growth hormone.

Option (c) effect of sex hormone on the secretion of growth hormone. The sex hormone helps in modifying and the growth-promoting effects of the growth hormone. Hence, the sex hormone has a permissive effect on the functioning of the growth hormone.

Option (d) given as both a and c. As the thyroid hormone and the sex hormones both have a permissive effect on the growth hormone, the option (a) and (c) are true. Hence, option (d) is the correct answer.

Explanation for incorrect answer:

Option (b) is given as the effect of insulin on glucose uptake by cells. It is not able to stimulate the formation of receptors for the hormone, like a permissive hormone. Hence, it is the wrong answer.

Option (e) is given as all of the above. As the insulin is not a permissive hormone, option (b) is incorrect. Hence, it is the wrong answer.

Conclusion

Thus, effect of thyroid hormones on growth and the effect of sex hormones on secretion of growth hormone, is an example of permissive hormones.