AP BIOLOGY

Detailed explanation-1: -Not all cells divide at the same rate. For example, neurons are a specialized type of cell in the nervous system, and they divide very rarely. By contrast, skin cells divide frequently in order to repair injuries or to replace old skin cells that have died. Similarly, cells divide at different speeds.

Detailed explanation-2: -No, all the cells do not divide all the time throughout their lives in animals. Hormonal influence regulates growth to a certain extent. Besides, most of the matured and differentiated cells like heart cells, neurons lose their ability of division. However, epidermal cells continue to divide.

Detailed explanation-3: -A typical proliferating human cell divides on average every 24 h. This division timing allows cells to synchronize with other physiological processes and with the environment.