"Dumpy" is a commonly used mutant phenotype in the nematode worm C.elegans.Two "Dumpy" individuals are crossed to each other,and this cross produces 210 "Dumpy" and 68 wild-type individuals.If one of the "Dumpy" individuals used in this cross was mated with a wild type,what "Dumpy": wild-type ratio would we observe in the offspring?
A)0:1
B)1:0
C)1:1
D)1:3
E)3:1

Question

Quizplus · Accepted Answer

The observed ratio of "Dumpy" to wild-type individuals (210:68) approximates a 3:1 ratio, suggesting that "Dumpy" is a recessive trait. When a homozygous recessive "Dumpy" individual is crossed with a heterozygous individual (which appears wild-type but carries one "Dumpy" allele), the expected offspring ratio is 1:1 for "Dumpy" to wild-type, as each offspring has a 50% chance of inheriting the "Dumpy" allele from the heterozygous parent.

"Dumpy" Is a Commonly Used Mutant Phenotype in the Nematode