1. Interphase: This is the longest phase of the cell cycle where the cell grows and copies its DNA.
* G1 Phase: The cell grows and synthesizes proteins and organelles.
* S Phase: DNA replication occurs, creating two identical copies of each chromosome.
* G2 Phase: The cell continues to grow and prepares for mitosis.
2. Prophase: The replicated chromosomes condense and become visible. The nuclear envelope breaks down, and the spindle fibers begin to form.
3. Metaphase: The chromosomes line up at the center of the cell (the metaphase plate) attached to the spindle fibers.
4. Anaphase: The sister chromatids (the two identical copies of each chromosome) separate and move to opposite poles of the cell.
5. Telophase: The chromosomes reach the poles and begin to decondense. The nuclear envelope reforms around each set of chromosomes, and the spindle fibers disappear.
6. Cytokinesis: The cytoplasm divides, forming two daughter cells, each with a complete set of chromosomes and organelles.
Key Points about Mitosis:
* Diploid: Somatic cells are diploid, meaning they have two sets of chromosomes (one set from each parent). Mitosis ensures that each daughter cell receives a complete set of chromosomes.
* Growth and Repair: Mitosis is essential for growth, development, and repair of tissues.
* Identical Copies: Mitosis produces two identical daughter cells, ensuring genetic continuity.
In contrast to mitosis, gametes (sex cells) reproduce through meiosis, which produces four genetically unique daughter cells with half the number of chromosomes.
