Which of the following is true when describing the permissive effect of a hormone? a) a permissive hormone can cancel out the effect of another hormoneb) this means that two hormones have a greater effect than just onec) the hormone can act alone when having an effect on a tissued) is usually the result of a second hormone's exposure on target cells

The correct answer is d) is usually the result of a second hormone's exposure on target cells

Explanation:

Permissiveness is described as the situation in which one hormone is not able to exert its full effect on the target cell and it requires the presence of another hormone to exert its full potential on the target cell.

Therefore the permissive effect is usually the result of the secondary hormone's presence or exposure on target cells. For example, thyroid hormone increases the effect of epinephrine on target cells by increasing its receptors on the target cell.

Without thyroid hormone, the epinephrine can not exert full effect on its target cell. Therefore the right answer is d.