Question

3. How is meiosis different from mitosis?

4. Where does meiosis occur in the body?

5. Why is genetic variation important for living organisms?
Vocabulary Practice
Match each term to its correct definition.
Term Definition
___ Gamete A. Process that produces eggs and sperm
___ Chromosomes B. Cells used for reproduction
___ Meiosis C. Structures that carry genetic information
Short Answer
6. Explain why meiosis must reduce the number of chromosomes by half.

Answer 1

3. How is meiosis different from mitosis?
- Purpose: Meiosis produces gametes (sex cells) for sexual reproduction; mitosis produces body (somatic) cells for growth and tissue repair.
- Number of divisions: Meiosis has two successive divisions (meiosis I and II); mitosis has one.
- Number and type of daughter cells: Meiosis yields four genetically different haploid cells (half the chromosome number); mitosis yields two genetically identical diploid cells (same chromosome number as the parent).
- Genetic variation: Meiosis includes homologous chromosome pairing, crossing over, and independent assortment, which create genetic variation; mitosis normally produces identical copies.
- When it happens: Meiosis occurs in reproductive cells; mitosis occurs throughout the body in somatic cells.

4. Where does meiosis occur in the body?
- In the gonads: testes in males (producing sperm) and ovaries in females (producing eggs). (In plants, meiosis occurs in sporangia such as anthers and ovules.)

5. Why is genetic variation important for living organisms?
- Provides raw material for evolution by natural selection, enabling populations to adapt to changing environments.
- Increases the chance that some individuals will survive new diseases, predators, or environmental stresses.
- Reduces the likelihood that harmful mutations will affect all individuals in a population.

Vocabulary Practice — Match each term to its correct definition.
- Gamete — B. Cells used for reproduction
- Chromosomes — C. Structures that carry genetic information
- Meiosis — A. Process that produces eggs and sperm

Short Answer
6. Explain why meiosis must reduce the number of chromosomes by half.
- Meiosis halves the chromosome number so that when two gametes fuse at fertilization the resulting zygote has the correct (species-specific) diploid number. If gametes were diploid, chromosome number would double each generation. Reducing to haploid therefore preserves a stable chromosome number across generations and allows genetic recombination without chromosome number increase.