Meiosis Flashcards
What is the process of meiosis?
1) Before Meiosis starts, the DNA unravels and replicates so there are two copies of each chromosome, called chromatids.
2) The DNA condenses to form two sister chromatids. These are joined in the Biddle by a centromere.
3) Meiosis I - the chromosomes arrange themselves into homologous pairs.
4) These are then separated, halving the chromosome number.
5) Meiosis II - the pairs of sister chromatids that make up each chromosome are separated (centromere is divided).
6) For Haploid cells that are genetically different from each other are produced.
What is a diploid?
When the Nucleus in a cell contains two sets of chromosomes.
What is a Haploid?
When the Nucleus in a cell contains one set of chromosomes.
What is the outcome of meiosis?
Daughter cells are genetically different from one another and the parent cell. Produces four daughter cells.
What happens in the first division?
Chromatids cross over - Chromatids twist around each other and parts of the chromatids swap over. They contain the same genes but now have different combinations of alleles.
What is independent assortment of chromosomes?
Describes how different genes independently separate from one another when reproductive cells develop.
Summarise Meiosis.
A type of cell devision that reduces the number of chromosomes in a parent cell by half to produce four reproductive cells called gametes.
