Reduced hormone concentration in the blood often causes target cells to
A) up-regulate receptors in order to increase cell sensitivity.
B) up-regulate receptors in order to decrease cell sensitivity.
C) down-regulate receptors in order to increase cell sensitivity.
D) down-regulate receptors in order to decrease cell sensitivity.

Question

Quizplus · Accepted Answer

When hormone levels are low, target cells often increase the number of receptors (up-regulate) to enhance sensitivity and improve the likelihood of hormone binding.

Reduced Hormone Concentration in the Blood Often Causes Target Cells