What is the term for cells stopping division when they form a single layer and touch?

The correct answer is density-dependent inhibition, which refers to the phenomenon where cells cease to divide when they come into contact with one another, forming a single layer. This process is crucial for regulating growth in tissues and is a key mechanism to maintain tissue architecture. It ensures that cells do not overgrow and form dense masses which could lead to issues such as tumors.

Density-dependent inhibition occurs when cells detect the presence of neighboring cells and respond by halting their cell cycle, preventing further division. This contact inhibition is vital in normal cellular processes and helps maintain homeostasis within tissues.

While apoptosis is a process of programmed cell death that can occur under certain conditions, it is not specifically linked to the mechanism of cells stopping division due to contact with other cells. Similarly, density-independent growth refers to growth patterns that do not rely on population density, and cell cycle arrest is a broader term that describes any stoppage in the cell cycle, which can occur for various reasons but does not specifically address the phenomenon of cells touching and ceasing division.