Meiosis Flashcards
All 6 cards in this deck
Where in the body does meiosis take place?
In the reproductive organs (e.g. testes and ovaries), to form gametes.
How many cells does meiosis produce from one cell, and what are they like?
Four gametes, all genetically different, each with a single set of chromosomes (half the normal number).
How does meiosis produce gametes that are genetically different?
A random chromosome from each pair goes into each gamete, giving different combinations of chromosomes.
What are the steps by which meiosis halves and fertilisation restores the chromosome number?
e.g. a human cell with 46 chromosomes- Chromosomes are copied and the cell divides twice: 4 gametes, each with 23 chromosomes.
- Two gametes fuse at fertilisation: 23 + 23 = 46 chromosomes.
- The new cell divides by mitosis to form an embryo, keeping 46 chromosomes in every cell.
What type of cell division does the fertilised egg use as it grows into an embryo?
Mitosis — the number of cells increases and, as the embryo develops, the cells differentiate.
True or false? Meiosis produces two genetically identical cells.
False. Meiosis produces four genetically different cells; mitosis produces identical cells.