Final answer:
The interference of 0.2 between three genes implies that the coefficient of coincidence is 0.8. This value reflects the observed frequency of double crossovers in relation to the expected number, and it can be used for constructing genetic maps and studying genetic linkage.
Step-by-step explanation:
The interference among three genes is a measure of the deviation from the expected frequency of double crossovers during genetic crossing over. The interference is calculated as 1 - coefficient of coincidence. Given that the question states the interference is 0.2, we can calculate the coefficient of coincidence by subtracting the interference from 1, which gives us 0.8. The coefficient of coincidence is a ratio of the observed number of double crossovers to the expected number and can provide insights into the genetic distance and linkage between alleles.
In genetics, specific characteristics resulting in a phenotypic ratio that totals 16 suggest a two-gene interaction, reminding us of Mendel's dihybrid cross pattern, which is 9:3:3:1. When genetics problems involve calculating recombination frequencies, it indicates genetic linkage. Perfectly unlinked genes will assort independently, which aligns with a recombination frequency of 0.5, while genes that are on the same chromosome may show lower recombination frequencies if they are linked.
Understanding the concept of interference and the coefficient of coincidence is important in constructing genetic maps based on recombination frequencies as initially proposed by Alfred Sturtevant, using map units or centimorgans (cM). Such genetic mapping helps infer the order of genes on a chromosome and estimate the likelihood of crossovers during meiosis, which is central to the study of genetics and inheritance.