Question

Often the results of breeding experiments do not follow expected Mendelian ratios. Instead of 3:1 or 9:3:3:1 ratios in the F2 generations, there may be results such as 1:2:1, 9:7, 9:3:4, or 7:1:1:7. How can you explain such ratios?

Answer 1

The deviations from expected Mendelian ratios in breeding experiments can be explained by factors such as genetic linkage, incomplete dominance, and multiple gene interactions.

Step-by-step explanation:

Mendelian ratios describe the expected phenotypic ratios of offspring in a breeding experiment based on the laws of probability. However, there are factors that can lead to deviations from these ratios.

One factor is genetic linkage, where certain genes are physically located close to each other on the same chromosome and tend to be inherited together.

Another factor is incomplete dominance, where neither allele is completely dominant over the other and the resulting phenotype is a blend of both alleles. Additionally, multiple gene interactions can also lead to different ratios, such as when two genes interact to produce a phenotypic ratio of 9:7.