1. Interphase: This is the longest phase of the cell cycle where the cell grows, copies its DNA, and prepares for division. Interphase is further divided into three sub-phases:
* G1 Phase (First Gap): The cell grows and synthesizes new proteins and organelles.
* S Phase (Synthesis): The cell replicates its DNA, ensuring each daughter cell receives a complete copy.
* G2 Phase (Second Gap): The cell continues to grow and prepares for mitosis (or meiosis). This includes synthesizing proteins needed for cell division.
2. M Phase (Mitotic Phase): This is the phase where the cell actually divides. It is further divided into two sub-phases:
* Mitosis: The nuclear division of the cell, where the duplicated chromosomes are separated into two identical nuclei. This process is further divided into four stages:
* Prophase: The chromosomes condense and become visible, the nuclear envelope breaks down, and the mitotic spindle forms.
* Metaphase: The chromosomes line up at the center of the cell (metaphase plate), attached to the mitotic spindle fibers.
* Anaphase: The sister chromatids separate and move to opposite poles of the cell, pulled by the spindle fibers.
* Telophase: The chromosomes reach the poles, the nuclear envelope reforms around the chromosomes, and the cytoplasm divides (cytokinesis).
* Cytokinesis: The division of the cytoplasm, creating two distinct daughter cells. This process usually begins during telophase and is completed shortly after.
Here's a simplified summary:
Interphase:
1. G1: Growth and preparation
2. S: DNA replication
3. G2: More growth and preparation for division
M Phase:
1. Mitosis: Nuclear division (prophase, metaphase, anaphase, telophase)
2. Cytokinesis: Division of the cytoplasm, creating two daughter cells
Important Note: The cell cycle is highly regulated and controlled by a complex network of proteins and signaling pathways. This ensures that the cell divides only when necessary and that the process occurs correctly to prevent errors and mutations.
