The Cell Cycle

Question 1

Why do somatic cells undergo cell division?

Answer 1

Growth
Repair – tissues and organs that have been damaged
Replacement – dying or dead cells

Question 2

What are the key events that occur at each stage of the cell cycle (IPMAT)?

Answer 2

Interphase:
- G1 (Growth 1): Rapid growth and metabolic activity.
- S (Synthesis): DNA replication, forming two identical sets.
- G2 (Growth 2): Prepares for division, centrioles replicate.

Mitosis:
- Prophase (Pro = Start): Chromatin condenses into chromosomes; centrioles move; nucleus changes.
- Metaphase (Meta = Middle): Chromosomes line up at the center.
- Anaphase (Ana = Backwards): Chromatids separate and move to opposite poles.
- Telophase (Telo = End): Chromosomes unwind, nuclei reform, and cell divides.

Think of “IPMAT” for Interphase, Prophase, Metaphase, Anaphase, Telophase.