The Cell Cycle

Scientific concepts and nature phenomena presented

• Cell cycle: the lifespan of a eukaryotic somatic cell, describing the sequence of cell growth and division.
• Somatic cells vs. sex cells: somatic cells are all body cells except sperm and egg cells.

Interphase (most of the cell’s life)

Interphase consists of three phases:

• G1 phase (growth 1 / gap 1): cell growth and performing normal functions.
  • Some specialized cells (e.g., muscle and nerve cells) may exit the cell cycle after G1 and do not divide again.
• S phase (synthesis): DNA replication occurs—copies of DNA are made.
• G2 phase (growth 2 / gap 2): the shortest/last part of interphase; the cell makes further preparations for cell division.

M phase (cell division)

M phase consists of two coordinated events:

• Mitosis: division of the nucleus
• Cytokinesis: division of the cytoplasm

Outcome: At the end of M phase, the cell produces two daughter cells that are identical to each other and to the original cell.

Structure / “methodology” outlined (phase sequence)

• Interphase
  • G1 → normal function and growth (may include exiting the cycle in some cells)
  • S → DNA replication
  • G2 → additional preparation for division
• Cell division
  • M phase
    • Mitosis (nucleus division)
    • Cytokinesis (cytoplasm division)

Researchers or sources featured

• None mentioned in the provided subtitles.