In a diploid plant species, an F₁ with the genotype Gg Ll Tt is test-crossed to a pure-breeding recessive plant with the genotype gg ll tt. The offspring genotypes are as follows: Genotype Number Gg Ll Tt   621 Gg Ll tt        3 Gg ll Tt     64 Gg ll tt   109 gg Ll Tt   103 gg Ll tt     67 gg ll Tt       7 gg ll tt   626 1600 What is the interference value for this data set?

Key Concepts

Test Cross

A test cross involves breeding an individual with a dominant phenotype but unknown genotype with a homozygous recessive individual. This method helps determine the genotype of the dominant individual based on the phenotypes of the offspring. In the given question, the F₁ plant (Gg Ll Tt) is test-crossed with a pure-breeding recessive plant (gg ll tt) to analyze the inheritance patterns.

Genotype Frequencies

Genotype frequencies refer to the proportion of different genotypes in a population. In the context of the question, the offspring genotypes and their counts provide data to calculate these frequencies. Understanding how to interpret these frequencies is crucial for determining genetic ratios and assessing the outcomes of genetic crosses.

Interference

Interference is a phenomenon in genetics where the occurrence of one crossover event reduces the likelihood of another crossover event occurring nearby. It is quantified by the interference value, which can be calculated using the observed and expected double crossover frequencies. In the context of the question, calculating the interference value helps understand the genetic linkage and recombination rates in the offspring.