Question

A cross between a dihybrid individual (heterozygous for two traits) and a homozygous recessive individual for the same two traits produces these phenotypes as offspring: parental phenotypes 526 and 542, and recombinant phenotypes 22 and 24.

A. these genes are not linked

B. these genes are on different chromosomes

C. these genes are linked

D. these genes sort independantly

can someone explain why is it c

Answer 1

The answer is C because the number of recombinant phenotypes is less than the parental phenotypes. This indicates that the two genes are linked on the same chromosome, and crossing over occurs less frequently between them during meiosis.

If the genes were not linked (answer A), then the expected ratio of parental phenotypes to recombinant phenotypes would be 1:1. However, we observe a greater number of parental phenotypes than recombinant phenotypes, indicating that the genes are linked.

If the genes were on different chromosomes (answer B), then they would assort independently during meiosis, and the ratio of parental to recombinant phenotypes would be 1:1.

Therefore, the correct answer is C: these genes are linked.