Question

“Upregulation” of hormone receptors refers to:
A. Increase in hormone receptor numbers with low hormone levels.
B. Increase in hormone receptor numbers with high neurotransmitter levels.
C. Increase in hormone receptor levels produced by an increase in hormone receptor numbers.
D. Decrease in hormone receptor levels is produced by a decrease in hormone receptor numbers.

Answer 1

Hint: When the number of receptors on the surface of target cells increases, the cells become more responsive to a hormone or another agent. In the third trimester of pregnancy, for instance, there is a rise in uterine oxytocin receptors, which promotes uterine smooth muscle contraction.

Complete Step by Step Answer:
All living cells can receive and process signals that originate outside their membranes, which they do through the use of proteins known as receptors, which are frequently found at the cell's surface embedded in the plasma membrane. When these signals interact with a receptor, they effectively direct the cell to do something, such as divide, die, or allow substances to be produced, or enter or exit the cell. The ability of a cell to respond to a chemical message is dependent on the presence of receptors that are tuned to that message. The more message-tuned receptors a cell has, the more the cell will respond to it.

Downregulation is the method by which a cell reduces the quantity of a cellular component, such as RNA or protein, in reaction to an external stimulus in the biological context of organisms' production of gene products. Upregulation refers to the complementary process of increasing such components.
Receptors are produced or expressed by the cell's DNA and can be increased or upregulated whenever the signal is weak or decreased or downregulated when the signal is strong.

The correct option is C.
Note: Neurotransmitters are chemicals neurons use to interact with one another and with their target tissues during the synaptic transmission process (neurotransmission).