Meiosis Flashcards
State the definition of a Crossing over
Pairs of chromosomes, when lined up, can swap bits of chromosome and there for gene.
Explain how independent assortment increases genetic variation.
The random lining up of chromosomes means there is no order to which allele will end up in which gamete during meiosis.
Where does crossing over occur?
It occurs at the Chiasma (chiasmata).
What does it mean when 2 genes are linked?
it means the genes are both on the same chromosome.
Explain how the loci of the genes affects the likelihood that they will stay linked following meiosis.
the closer together the loci of 2 genes the more likely it is that they will stay linked. This is because crossing over is less likely to split them apart.
Explain what crossing over is and how it leads to genetic variation.
Before first division of meiosis, homologous pairs of chromosomes come together and pair up. The chromatids twist together around each other and bits of chromatids break and rejoin onto the other chromatid. The chromatid now contain different combinations of alleles, so each of the 4 daughter cells will contain chromatids with different combinations of alleles.
Explain how independent assortment leads to genetic variation.
Independent Assortment means the chromosome pairs can split up in any way. So the cells will contain any combination of maternal and paternal chromosomes with different alleles.
