Cell cycle — Science definition
Defined in 2 courses:
- The sequence a cell passes through between divisions: a long growth phase including DNA replication, then division, with checkpoints controlling progress. (Life Science & Scientific Inquiry)
- The full, repeating sequence of growth, DNA copying, and division that a cell passes through. (Life Science: Biology)
Where it is taught
- The Cell Cycle & Mitosis — Genes, Cell Division & Heredity, Life Science & Scientific Inquiry, Grade 7
- Mitosis & the Cell Cycle — Cell Division, Reproduction & Development, Life Science: Biology, Grade 10
In use
Getting two metres of DNA copied and then divided evenly between two cells, millions of times a second, without losing or duplicating anything, is a serious engineering problem — and the cell cycle is the solution.
The Cell Cycle & Mitosis
But a cell cannot simply split in half whenever it likes — it moves through an orderly, repeating sequence called the cell cycle, and dividing is only the final act.
Mitosis & the Cell Cycle
Questions using cell cycle
Problem 1
- Cells begin making sex cells instead of body cells
- DNA is no longer copied before division
- Mutations damage the genes that control the cell cycle, so cells divide uncontrollably and ignore normal stop signals
- The cell cycle stops completely and no cells ever divide again
Answer and explanation
Mutations damage the genes that control the cell cycle, so cells divide uncontrollably and ignore normal stop signals
Cancer arises when the checkpoint-control genes are mutated, letting cells divide out of control instead of stopping when they should.
Problem 2
- Prophase
- The S phase of interphase
- Anaphase
- Cytokinesis
Answer and explanation
The S phase of interphase
Replication occurs in the S phase of interphase, before mitosis begins, so each chromosome enters mitosis already duplicated.