Question

In which stage of meiosis, crossing over takes place?

• A. Pachytene
• B. Leptotene
• C. Metaphase
• D. Anaphase

Answer 1

The correct option is A Pachytene

Crossing over mainly takes place in the pachytene stage of the prophase I of the meiosis. During crossing over, the homologous chromosomes exchange their genetic material which leads to the formation of recombinants. It takes place by enzyme recombinase which is made up of exonuclease, endonuclease, helicase and R protein. The endonuclease creates the nick. The gap in the nick is created by an exonuclease. The separation of chromatid segments carried by helicase and finally the exchanged segments are reunited by R protein.

So, the correct answer is option A.