Which of the following statements is incorrect? Down-regulation may occur if a hormone is present in excess. Down- regulation results in an increase in the number of target-cell receptors. In up-regulation, a target cell becomes more sensitive to a hormone. If a hormone is present in excess, the number of target cell receptors decreases.

"Down- regulation results in an increase in the number of target-cell receptors" statements is incorrect.

Option: B

Explanation:

The generation of gene products with the biological context of organisms: down-regulation is a mechanism by which a cell reduces the amount of a cellular product, such as RNA or protein, in accordance to an external stimulus, for instance, on type 2 diabetes, insulin receptors may be downregulated.

The supplementary process involving these component increments is called up-regulation. Enhanced uterine oxytocin receptors occur in pregnancy's third trimester, inducing a contraction of the smooth uterine muscle.