Epistasis and Complementary Gene Action

What is the term for the phenomenon where one gene masks the effect of another gene?

In Labrador retrievers, coat color is determined by epistatic interactions. What phenotypic ratio is indicative of recessive epistasis in a dihybrid cross?

In sweet peas, two genes (C and P) are involved in the production of purple flower color. What phenotypic ratio is indicative of complementary gene action?

A plant with genotype AABB is crossed with a plant with genotype aabb. In the F2 generation, a 12:3:1 phenotypic ratio is observed. Which type of epistasis is likely occurring?

In mice, coat color is controlled by multiple genes. If gene 'C' controls color expression and 'cc' results in albinism, how would you describe the relationship of gene 'C' to other color genes?

In wheat, seed shape is determined by two genes, T and V. A cross between two TtVv plants yields a 15:1 phenotypic ratio in the F2 generation. What type of gene interaction is indicated by this ratio?

What is the purpose of performing a complementation test?

In the context of epistasis, what does it mean for a gene to be 'hypostatic'?

In summer squash, fruit color is determined by dominant epistasis, resulting in a 12:3:1 ratio. If 'A' allows color and 'B' masks color, what genotype(s) would produce white fruit?

Considering a biochemical pathway where gene A produces an intermediate X, and gene B uses X to produce a final product Y. If a mutation in gene A completely blocks the production of X, what is the most likely epistatic relationship between A and B?

Two true-breeding mutant lines of petunias both produce white flowers instead of the wild-type purple. You cross the two lines and observe that all of the F1 progeny have purple flowers. What does this result suggest about the mutations in the two parental lines?

In a population of snails, albinism is observed at a higher rate than expected under Mendelian inheritance. Crossing albino snails often yields only albino offspring, but occasionally, a cross between two albino snails yields some pigmented offspring. Which genetic phenomenon is most likely responsible?

A researcher is studying flower color in a new species of plant. They cross two true-breeding lines, one with red flowers and one with white flowers. All the F1 offspring have purple flowers. When the F1 plants are self-crossed, the F2 generation shows a ratio of 9 purple: 3 red: 4 white. Which of the following genetic phenomena is likely occurring?

A dihybrid cross involving two genes that influence fruit shape in a certain plant species yields an unusual phenotypic ratio in the F2 generation. The ratio is 9:6:1, where 9/16 of the plants have round fruit, 6/16 have oval fruit, and 1/16 have long fruit. Assuming Mendelian inheritance at each locus, which type of gene interaction is most likely to explain this ratio?

Imagine you are studying a novel metabolic pathway in bacteria, where gene X encodes an enzyme that converts a colorless precursor into compound A (yellow), and gene Y encodes an enzyme that converts compound A into compound B (blue). You isolate a mutant strain of the bacteria that has a non-functional gene X. If gene Y is still functional in this mutant strain, what color would you expect the bacteria to be, and what type of epistasis is occurring?