meiosis

Question 1

what is meiosis?

Answer 1

a form of cell division that produces four genetically different haploid cells (half number of chromosomes found in parent cell) known as gametes

Question 2

what happens during meiosis I?

Answer 2

1. homologous chromosomes pair to form bivalents
2. crossing over (exchange of sections of genetic material) occurs at chiasmata
3. cell divides into two, homologous chromosomes separate randomly, each cell contains either maternal or paternal copy

Question 3

what are homologous chromosomes?

Answer 3

• pair of chromosomes with genes at the same locus
• 1 maternal and 1 paternal
• some alleles may be the same while others are different

Question 4

what happens during meiosis II?

Answer 4

1. independent segregation of sister chromatids
2. each cell divides again, producing 4 haploid cells

Question 5

how does meiosis produce genetic variation?

Answer 5

• crossing over during meiosis I
• independent assortment (random segregation) of homologous chromosomes and sister chromatids
• result in new combinations of alleles