True or False: Target cells must have receptors to recognize a hormone.

The correct response is that it is true that target cells must have receptors to recognize a hormone. Hormones exert their effects on specific target cells through binding to their respective receptors. These receptors are typically proteins located on the cell membrane or inside the target cell.

When a hormone binds to its receptor, it initiates a series of cellular responses that lead to the desired effect, such as changes in gene expression, metabolism, or cellular function. Without the presence of these receptors, target cells would be unable to recognize or respond to the hormone, which would mean that the hormone's signaling function would be ineffective.

This principle is fundamental to endocrinology and explains how hormones can exert highly specific effects on particular tissues while circulating throughout the body. Therefore, the statement that target cells must have receptors to recognize a hormone is indeed true.