Crossing Over

Question 1

When does crossing over happen?

Answer 1

During prophase one

Question 2

What happens during crossing over?

Answer 2

2 homologous chromosomes pair up and exchange genetic info

Question 3

What are the steps of crossing over?

Answer 3

Homologous pairs line up
Chromatids of each pair become twisted
Section of chromatid breaks off and rejoins chromatids of the other homologous chromosomes

Question 4

What is a chiasma?

Answer 4

Point where the chromatids twist

Question 5

How many daughter cells are produced when there is no crossing over?

Answer 5

2 versions of possible daughter cells produced

Question 6

How many daughter cells are produced when there is crossing over?

Answer 6

4 possible versions of possible daughter cells produced

Question 7

How does crossing over can contribute to genetic variation?

Answer 7

Sections of chromatids exchanged
Sections have different alleles
New combination of alleles