Why do linked genes give us different ratios in our punnett squares that genes found on separate chromosomes?
Linked genes are genes located on the same chromosome, usually inherited together in a genetic cross, that is, lower frequency of crossing over. I am just curious where did u find this statement. If I am not wrong punnett squares give theoretical ratios, that is, the expected ratio, where linkage is not taken into account. So it is the observed ratio that gives different ratios, not the punnett squares. Here’s an example: A, a, represents alleles for trait A; B, b represents alleles for trait B Genes for trait A and trait B are linked/found on the same chromosome i.e. A & B are found on one chromosome while a & b are found on another chromosome. During gamete formation from F1, a higher proportion of gametes would carry the parental genotypes – AB and ab. Crossing over between non-sister chromatids during meiosis may occur to form recombinant gametes – Ab and aB. Since crossing over is a chance event, there are lower chances of getting recombinant gametes, resulting in a smaller propor
