Do genes always assort independently?

• A. Yes, always
• B. No
• C. Only in the F1
• D. Only if genes are unlinked

Answer: (B)

Independent assortment only holds when the loci are unlinked, meaning they reside on different chromosomes or far apart on the same chromosome so recombination can separate them freely. In practice, many genes are linked because they sit close together on the same chromosome, so they tend to be inherited together rather than independently. Crossing over during meiosis can create some recombinant combinations, but the proportions are not guaranteed to be 1:1, so the alleles do not assort independently in those cases. So, no, genes do not always assort independently. It’s true that unlinked genes will, but not all gene pairs are unlinked. The option suggesting it happens only if unlinked describes the condition under which independence occurs, not a universal rule.