What factor most determines whether two genes will assort independently?

What factor most determines whether two genes will assort independently?

• A. Their physical distance on a chromosome
• B. Their expression pattern
• C. Their mutation rate
• D. Whether they are on the same chromosome or not

Answer: (D)

Whether two genes assort independently depends on whether they are on separate chromosomes or are linked on the same chromosome. If they sit on different chromosomes, their alleles sort into gametes independently during meiosis, so all allele combinations appear in roughly equal proportions. If the genes are on the same chromosome, they are linked and tend to be inherited together; crossing over during meiosis can separate them, but independence is not guaranteed and depends on how far apart they are (the greater the distance, the higher the chance of recombination). The other factors—expression pattern, mutation rate, or the mere distance between genes on the same chromosome—do not determine independent assortment on their own.

Whether two genes assort independently depends on whether they are on separate chromosomes or are linked on the same chromosome. If they sit on different chromosomes, their alleles sort into gametes independently during meiosis, so all allele combinations appear in roughly equal proportions. If the genes are on the same chromosome, they are linked and tend to be inherited together; crossing over during meiosis can separate them, but independence is not guaranteed and depends on how far apart they are (the greater the distance, the higher the chance of recombination). The other factors—expression pattern, mutation rate, or the mere distance between genes on the same chromosome—do not determine independent assortment on their own.