Cells grow by increasing their size and accumulating more mass. This growth occurs in the G1 phase of the cell cycle, which is tightly coordinated with the subsequent phases: DNA synthesis (S phase) and mitosis (M phase).
Cell growth is influenced by external cues such as:
- Growth factors: These are signaling molecules that promote cell growth and division.
- Hormones: These are chemical messengers that can regulate cell growth and development.
- Nutrient availability: Cells need adequate nutrients to fuel their growth processes.
For example, in dividing mammalian cells, growth factors, hormones, and nutrient availability work together to initiate and sustain cell growth during the G1 phase.
Once a cell has grown sufficiently, it can then enter the S phase and duplicate its DNA. Following this, the cell enters the M phase and divides into two daughter cells.
This process of growth and division continues throughout an organism's lifetime, enabling tissues and organs to develop and maintain themselves.
