2016 Meiosis and variation

Question 1

How does Anaphase I give rise to genetic variation?

Answer 1

• random assortment of chromosomes in Anaphase I;
• produces new combinations of chromosomes and the genes they carry from each homologous pair;
• the resulting nuclei thus have new combinations of the genes present;

Question 2

How does Anaphase II give rise to genetic variation?

Answer 2

• random assortment of chromatids during Anaphase II;
• produces new combinations of alleles in the regrouped chromatids;
• resulting nuclei thus have new combinations of the alleles present;

Question 3

How does the chiasmata give rise to genetic variation?

Answer 3

• chiasmata form between chromatids of different but homologous chromosomes;
• thus moving alleles from chromosome to chromosome into new combinations;
• thus modifying the linkage groups present;

Question 4

Describe the structural differences in chromosomes of Meiosis 1 to mitosis

Answer 4

In meiosis

• chromosomes would be replicated into chromatids;
• chiasmata would be showing between chromatids of homologous chromosomes;

Question 5

Describe the difference in arrangement of chromosomes in Meiosis 1 and mitosis

Answer 5

in meiosis

• chromosomes would be arranged into homologous pairs;
• with centromeres attached to the opposite spindles;