AP BIOLOGY

LABORATORY REVIEW

MITOSIS AND MEIOSIS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
During which phase of meiosis does crossing-over occur?
A
prophase I
B
prophase II
C
metaphase I
D
metaphase II
Explanation: 

Detailed explanation-1: -Crossing over is an enzyme-mediated process, where the exchange of genetic material between non-sister chromatids of homologous chromosomes takes place. It occurs at the pachytene stage of prophase I of meiosis.

Detailed explanation-2: -Crossing over occurs during the pachytene stage of prophase in meiosis, however the chiasma are visible during. No worries!

Detailed explanation-3: -Explanation: During prophase I, homologous chromosomes pair with each other and exchange genetic material in a process called chromosomal crossover. The exchange occurs in segments over a small region of homology (similarity in sequence, ie., the same alleles).

Detailed explanation-4: -During meiosis, crossing-over occurs at the pachytene stage, when homologous chromosomes are completely paired.

There is 1 question to complete.