Somatic Cells and Cell Cycle
Your body relies on somatic cells for growth and repair through a carefully orchestrated process of division. These body cells follow a cell cycle with four main stages: G1, S, G2, and the Mitotic Stage.
Most of a cell's life is spent in Interphase, which includes three phases: G1 (where the cell grows and doubles in size), S (where DNA synthesis and replication occur), and G2 (when proteins needed for cell division are synthesized). After interphase comes Mitosis, where the spindle distributes chromosomes to daughter cells using microtubules organized by centrosomes.
Mitosis maintains a constant chromosome number and occurs in four phases: Prophase, Metaphase, Anaphase, and Telophase. Cytokinesis follows, physically dividing the cytoplasm into two daughter cells. In animals, this happens through a cleavage furrow with a contractile ring, while plants form a cell plate using vesicles from the Golgi apparatus.
Fun Fact: Plants don't have centrioles or asters like animal cells do! Instead, they rely on specialized tissues called meristems that can divide throughout the plant's life, allowing trees to grow taller and wider.
Cell division isn't always beneficial - sometimes cells need to die. Apoptosis is programmed cell death regulated by enzymes called caspases. Prokaryotes (bacteria and archaea) divide differently through binary fission, creating two identical daughter cells, each with a single chromosome.
