Crossing over occurs at - Vidyadip

MCQ

Crossing over occurs at

A
Single strand stage
B
Two strand stage
✓
Four strand stage
D
Eight strand stage

✓

Answer

Correct option: C.

Four strand stage

c
During pachytene substage of prophase$-I$ of meiosis, the chromosomes are tetravalent i.e., contain two chromatids with each chromosome arms. Crossing over during this substage, which involves the exchange of segments between the non-sister chromatid of homologues.

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