Meiosis
Vocabulary
| English | Chinese | Pinyin |
|---|---|---|
| gametes | 配子 | pèi zi |
| meiosis | 减数分裂 | jiǎn shù fēn liè |
| variation | 变异 | biàn yì |
Making gametes 配子
- Gametes must carry only half the chromosomes, so that fertilisation restores the full set.
- The special division that does this is meiosis 减数分裂.
Practice
Meiosis produces how many cells from one parent cell?
Meiosis makes four gametes.
Practice
Each cell made by meiosis has:
Gametes carry half the chromosomes.
Practice
Meiosis produces the sex cells, also called ______.
Gametes have half the chromosome number.
What meiosis is
- Meiosis produces four cells, each with half the chromosome number.
- These cells are the gametes (sperm and eggs).
A Punnett square for Bb x Bb gives a 3:1 ratio of dominant to recessive
Explore
Meiosis
Meiosis makes gametes — four cells, each with HALF the chromosomes and all different.
Practice
Meiosis is important because it:
Meiosis mixes genes, producing variation.
It creates variation 变异
- Meiosis mixes the genes, so each gamete is genetically different.
- This is a major source of variation in sexual reproduction.
Practice
Halving the chromosome number stops it doubling each generation.
Fertilisation then restores the full number.
Mitosis vs meiosis
- Mitosis: 2 identical cells, full chromosome number — growth/repair.
- Meiosis: 4 varied cells, half the number — making gametes.
Watch out
Meiosis halves the chromosome number; mitosis keeps it the same. This halving is essential — without it, the chromosome number would double every generation at fertilisation.
You've got it
Key idea
- meiosis makes four cells, each with half the chromosome number — the gametes
- it mixes genes, creating variation
- mitosis = 2 identical (full number); meiosis = 4 varied (half number)