Cell response to a ligand is influenced by which of the following factors?

• A. Ligand's chemical structure
• B. Number of receptors on target cell
• C. Receptor's location in the body
• D. Ligand's size

Answer: (B)

The number of receptors on a target cell is a critical factor that influences the cell's response to a ligand. When a ligand binds to its receptor, it typically initiates a signaling cascade that leads to a specific cellular response, such as gene expression, metabolism changes, or alterations in cell behavior.

Having a greater number of receptors on the cell surface increases the likelihood of ligand-receptor interactions occurring. This relationship means that more receptors can bind to the ligand simultaneously, thereby amplifying the cellular response. Conversely, if there are fewer receptors available, the response may be diminished, even if a significant amount of ligand is present.

The dynamics of receptor density can also play a role in how cells adapt to different physiological conditions, including receptor upregulation or downregulation in response to varying levels of ligand exposure over time. Thus, receptor quantity is essential in understanding how signals are transmitted and how effectively a cell can respond to external stimuli.