The Cell Cycle, Mitosis, and Meiosis
Division and Genetic Continuity
Cell cycle overview
The cell cycle includes interphase and the mitotic phase. DNA is replicated before division so each daughter cell can receive a complete genome.
Mitosis and meiosis
Mitosis produces genetically identical daughter cells for growth and repair. Meiosis produces haploid gametes and increases variation through crossing over and independent assortment.
Why meiosis matters
Meiosis reduces chromosome number by half, making sexual reproduction possible without doubling chromosomes every generation.
Which event is unique to meiosis and not typical of mitosis?
Crossing over occurs during meiosis I and creates new allele combinations.
Correct answer: Crossing over
What is the ploidy of a human gamete?
Human gametes contain one set of chromosomes, so they are haploid.
Correct answer: Haploid, or chromosomes
Mitosis vs meiosis
| Feature | Mitosis | Meiosis |
|---|---|---|
| Number of divisions | One | Two |
| Products | Two identical cells | Four nonidentical cells |
| Chromosome number | Maintained | Reduced by half |
| Function | Growth and repair | Gamete formation |