Which pair of genes is expected to have the highest recombination rate during meiosis?

• A. Genes located farthest apart on the same chromosome
• B. Genes located on the same locus
• C. Genes located very close together on the same chromosome
• D. Genes located on different arms of the same chromosome

Answer: (A)

Verified step by step guidance

1. Understand that recombination rate between two genes during meiosis depends on their physical distance on the chromosome; the farther apart two genes are, the higher the chance of crossover events between them.
2. Recall that genes located at the same locus occupy the exact same position on homologous chromosomes, so they cannot recombine because they are essentially the same gene position.
3. Recognize that genes very close together on the same chromosome have a low recombination rate because crossovers between them are rare.
4. Consider that genes on different arms of the same chromosome can have moderate recombination rates, but this depends on the length of the chromosome arms and the distance between the genes.
5. Conclude that the pair of genes expected to have the highest recombination rate are those located farthest apart on the same chromosome, as the probability of crossover increases with distance, which can be expressed as recombination frequency approaching 50% for genes very far apart.