Which is the best description or sample of epistasis? a) Alletes at one locus can ide or mask the effect of alles another locus
b) When one alde completely masks the other alleles in an alleic series of a gene
c) When the heterorypote shows a phenotype that is intermediate between the two corresponding homarypotes
d) People who are blood type AB
e) When the hemoglobin type is determined by two genes--alpha like globins and beta like globins.

a) Alleles at one locus can hide or mask the effect of alleles at another locus

Explanation:

Gene interactions happen between genes at different levels and have implications in the phenotypic expression, causing a wide genetic variability.  

Epistasis means "interruption" and refers to interactions between genes located in different loci in the same chromosome. An “epistatic gene” can alter, influence, or suppress the expression of a "hypostatic gene". Epistatic genes might be either recessive or dominant. When the epistatic gene is recessive, the interaction is known as "recessive epistasis".  While when the epistatic gene is dominant, the interaction is known as "dominant epistasis"  

Observing the altered phenotype proportions of the offspring can reveal which interaction is operating in the trait determination.  

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