Question

Distance between two linked genes upon a chromosome measured in cross-over units is

• A. Ratio of crossing over between them
• B. Cross-over value
• C. Number of other genes between them
• D. Both A and B

Answer 1

Answer: (D)

Both A and B

Frequency of cross-over can be affected by location (crossing over is repressed close to the centromere) and proximity to another crossover. Also, since scoring of recombinant offspring ignores what else might be going in between the two genes, the number of recombination events is always underestimated because double cross-overs are missed. Thus, the correct answer is option D.