Cell division - meiosis Flashcards
What is meiosis?
A way of producing gametes (sex cells).
Where does meiosis take place?
In the male and female reproductive organs, testes and ovaries.
How many cell divisions are there in meiosis?
2
How many cells are produced in meiosis?
4
How many chromosomes do gametes have?
23
When is meiosis used?
To produce sex cells.
What is the first step of meiosis?
There is a cell with 2 pairs of chromosomes (diploid cell).
What is the second step of meiosis?
Each chromosome replicates itself.
What is the third step of meiosis?
Chromosomes move to opposite poles.
What is the fourth step of meiosis?
Cell divides for first time.
What is the fifth step of meiosis?
Copies now separate and the second cell division takes place.
What is the result of meiosis?
Four haploid cells are produced each with half number of chromosomes as parent cell.
How are gametes different?
They’re all genetically different.
Why is meiosis important?
Because it halves number of chromosomes in gametes meaning fertilisation can restore full number of chromosomes.
Why is genetic variation important?
To stop the inheritance of diseases and bad alleles which are genetically inherited.
