Which of the following is responsible for differentiation, or specialization, of cells?

Hormones are signaling molecules that travel through the bloodstream and bind to receptors on cells. This binding triggers a cascade of events that can lead to changes in gene expression, cell morphology, and cell function.

Different hormones play different roles in cell differentiation. For example, thyroid hormone is essential for the differentiation of many types of cells, including nerve cells, muscle cells, and bone cells. Estrogen and testosterone are responsible for the differentiation of sex-specific cells, such as oocytes and sperm.

Hormones can also work together to control cell differentiation. For example, growth hormone and thyroid hormone work together to promote the differentiation of bone cells.