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The cell cycle distinguishes eukaryotic cells from prokaryotic cells. It traces a cell’s journey from birth—after cytokinesis of its parent—to its own division into two genetically identical daughter cells.
Interphase occupies the majority of the cycle’s time and prepares the cell for mitosis. During this period, the cell grows, duplicates its organelles, and replicates its DNA.
Immediately after birth, the cell appears quiescent under the microscope, but it is actively accumulating energy and nucleotides required for DNA synthesis.
DNA replication occurs in the nucleus, producing two identical sister chromatids for each of the 46 chromosomes. These chromatids remain physically linked.
The cell completes organelle duplication, grows further, and conducts quality‑control checks to identify any replication errors before proceeding to mitosis.
The M phase starts with mitosis and ends with cytokinesis. Mitosis subdivides into four phases—prophase, metaphase, anaphase, telophase—each ensuring accurate chromosome segregation.
Chromosomes condense and become visible. The mitotic spindle forms as centrioles move to opposite poles, and the nuclear envelope dissolves.
Chromosomes align at the metaphase plate. Microtubules from the spindle attach to kinetochores, positioning each chromosome so that sister chromatids face opposite poles.
Spindle fibers contract, pulling sister chromatids apart at the centromeres toward opposite poles. Cytokinesis initiation begins concurrently.
Chromosomes decondense, nuclear membranes re‑form around each set, and the cell prepares for division of its cytoplasm.
Cytokinesis finalizes cell division, creating two daughter cells. In animal cells, the contractile ring constricts the cleavage furrow, while in plant cells, a new cell wall forms at the metaphase plate, partitioning the cytoplasm.
