Meiosis

• How many divisions in meiosis?

  2
• Are daughter cells identical?

  Yes
• Is the chromosome number halved?

  Yes
• What happens at anaphase 1?

  homologous chromosomes separate
• What happens at anaphase 2?

  Sister chromatids separate
• Name for crossed over homologous chromosomes?

  Bivalent
• Meiosis happens when the diploid goes to a …

  Haploid
• How many haploids at the end of meiosis?

  4
• Non sister chromatids

  Same place On different alleles
• Sister chromatids

  On the same alleles
• Why are homologous chromosomes not identical?

  One is maternal and one paternal so alleles are different
• Why is halving the chromosomes number important?

  so the normal number is restored at fertilisation
• Fertilisation is…

  Random
• When does crossing over happen?

  prophase 1
• When does independent segregation happen?

  Metaphase 1
• What is crossing over?

  genes wrap around each other and the exchange of alleles between homologous chromosomes
• Is crossing over random?

  yes
• How does crossing over create variation?

  leads to unique allele combinations
• Recombinant chromosomes meaning?

  not found in parents
• what is a chiasma?

  point where homologous chromosomes exchange alleles
• Non recombinant meaning?

  found in parents
• What is independent segregation?

  Random alignment of homologous chromosomes either side of the equator
• Why does independent segregation create variation?

  It makes unique allele combinations
• Autosomally linked genes

  On the same side of the equator in metaphase 1
• Not autosomally linked genes

  On different chromosomes