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[A] : Crossing over takes place during p...

[A] : Crossing over takes place during pachytene stage .
[R] : It is a process of inter change of chromatin material between one sister chromatid of each homologous chromosome .

A

If both A and R are true and R is the correct explanation of A

B

If both A and R are true but R is not the correct explanation of A

C

If A is true and R is false

D

If both A and R are false

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