How could crossing over affect the distribution of the four alleles: A, a, B, and b?

A. Crossing over would always keep A and B together on the same chromosome, and keep a and b together on the same chromosome.

B. Crossing over would always put A and B on different chromosomes, and always put a and b on different chromosomes.

C. Crossing over would sometimes, but not always, exchange the positions of A and a, and of B and b, on homologous chromosomes.

D. Crossing over would sometimes, but not always, delete one or more of the four alleles from both homologous chromosomes.

Question

Thomas Clements

Biology

25 April, 05:05

How could crossing over affect the distribution of the four alleles: A, a, B, and b?

A. Crossing over would always keep A and B together on the same chromosome, and keep a and b together on the same chromosome.

B. Crossing over would always put A and B on different chromosomes, and always put a and b on different chromosomes.

C. Crossing over would sometimes, but not always, exchange the positions of A and a, and of B and b, on homologous chromosomes.

D. Crossing over would sometimes, but not always, delete one or more of the four alleles from both homologous chromosomes.

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Answers (1)

Know the Answer?

Damian Esparza · Answer 1

C is the best answer

Explanation:

Crossing over is generally random and not goal oriented. So it does not always happen but it is likely to occur is it is an evolutionary advantage since it makes us more diverse. It involves the reciprocal exchange (NOT deletion) of segments between two homologs.