Assertion: Crossing over leads to recombination of genetic material on the two chromosomes.
Reason: Crossing over is the exchange of genetic material between two homologous chromosomes.

Options

A. If both assertion and reason are true and reason is the correct explantion of assertion
B. If both assertion and reason are true but reason is not the correct explnantion of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

A

Explanation

Croosing over a recombination occurs during pachytene. Recombination involves mutual exchange of the corresponding segments of non-sister chormatids of homologous chromosomes. It takes place by breakeage and reunion of chromatid segments. Breakeage, called nicking, is assisted by an enzyme endonulease and renuion, termed annealing, is aided by a nenzyme ligase. Crossing over leads to recombination of genetic material on the two chromosmes.