Cell cycle
The cell cycle is the series of events that occurs in a cell as it grows and divides into two daughter cells. It consists of four main phases:
1. G1 Phase (Gap 1): The cell grows and carries out its normal functions. It prepares for DNA replication.
2. S Phase (Synthesis): DNA replication occurs during this phase. The cell copies its DNA in preparation for cell division.
3. G2 Phase (Gap 2): The cell continues to grow and prepare for mitosis (cell division). It checks for any errors in DNA replication and repairs them if necessary.
4. M Phase (Mitosis): The cell divides into two daughter cells. This phase consists of several sub-phases including prophase, metaphase, anaphase, and telophase.
After mitosis, the daughter cells enter the G1 phase again and the cell cycle starts anew. The cell cycle is regulated by several checkpoints to ensure that the cell is ready for each phase and to prevent abnormal cell growth.
The cell cycle refers to the series of events that take place in a cell leading to its division and duplication. It consists of several distinct phases which include:
1. Interphase: This is the longest phase of the cell cycle, during which the cell grows and carries out its normal functions. Interphase can be further broken down into three subphases:
- G1 phase (Gap 1 phase): The cell grows in size and prepares for DNA replication.
- S phase (Synthesis phase): DNA replication occurs, resulting in the formation of identical copies of the cell's genetic material.
- G2 phase (Gap 2 phase): The cell continues to grow and prepares for cell division.
2. Mitosis: This phase involves the division of the cell's nucleus into two identical daughter nuclei. Mitosis is further divided into several stages:
- Prophase: Chromosomes become visible, the nuclear membrane breaks down, and the spindle apparatus forms.
- Metaphase: Chromosomes align along the cell's equator and attach to spindle fibers at their centromeres.
- Anaphase: Sister chromatids separate and move towards opposite poles of the cell.
- Telophase: Two new nuclei form around the separated chromosomes, and the cell begins to divide.
- Cytokinesis: The division of the cell's cytoplasm, resulting in the formation of two identical daughter cells.
Overall, the cell cycle ensures the growth, development, and maintenance of multicellular organisms by allowing cells to divide and produce new cells.