Mamidi Rambabu

The cell cycle begins with interphase, which is a preparatory stage. During this phase, all major organelles, proteins, and the DNA replicate. Interphase is divided into three sub-phases, each responsible for a specific task: G₁ phase: The cell grows in size and remains metabolically active, carrying out all essential biochemical activities. S phase: DNA replication takes place here. The number of chromosomes stays the same, but the amount of DNA in each chromosome doubles. Centrioles also duplicate, preparing for the division of centromeres. G₂ phase: This phase is marked by the synthesis of proteins needed for cell division. After interphase, the M phase (Mitotic phase) starts, which includes four stages: 1. Prophase: Chromosomes condense, and the centrioles start moving toward opposite poles of the cell. 2. Metaphase: Chromosomes align at the center of the cell, forming the metaphase plate. Centrioles reach the poles and extend spindle fibers toward the centromeres. 3. Anaphase: Spindle fibers pull the centromeres apart, splitting each chromosome into two identical ones. This is why mitosis is considered an equational division—there is no genetic variation, and each new cell receives an identical set of chromosomes. 4. Telophase: The condensed chromosomes begin to uncoil. Nuclear membranes and other organelles like mitochondria reappear, restoring the original cell structure.