Why are dizygotic twins less likely to show concordance for a monogenic trait than monozygotic twins?
A)Dizygotic twins share fewer allele sequences in common than monozygotic twins.
B)It is possible for dizygotic twins to have different fathers, and monozygotic twins always have the same father.
C)Gene expression in monozygotic twins is less influenced by environmental factors than that of dizygotic twins.
D)Because of their identical appearance, monozygotic twins are more likely to be raised together and share a common environment than are dizygotic twins.

Question

Quizplus · Accepted Answer

Dizygotic twins have no more common allele sequences than do any other pair of siblings, whereas monozygotic twins initially have all allele sequences in common, although some changes do occur over time. There is no overall difference in the influence of the environment over gene expression between the two twin types. Although it is possible for dizygotic twins to have different fathers, this is a very rare event and is not the main factor in the decreased concordance for expression of a monogenic trait.

Why Are Dizygotic Twins Less Likely to Show Concordance for a Monogenic