Which of the following is TRUE with regard to sources of variability?
A)The chromosomes in the zygote are not exact copies of those in the mother's ovaries and the father's testes.
B)Fraternal twins develop from a single zygote that splits into two genetically identical replicas.
C)For each genotype,only a single corresponding phenotype can be expressed.
D)Identical twins develop from separate eggs and separate sperm.

Question

Quizplus · Accepted Answer

Variability can arise due to mutations or differences in genetic material inherited from parents. The chromosomes in the zygote are not exact copies of those in the mother's ovaries and the father's testes, as they undergo recombination and random assortment during meiosis. This leads to variability in the genetic makeup of the offspring.

B) is false, as fraternal twins develop from separate eggs fertilized by separate sperm, and are genetically distinct.

C)is false, as different environmental factors can influence the expression of the same genotype, leading to variations in phenotype.

D)is false, as identical twins develop from a single zygote that splits into two genetically identical replicas.

Which of the Following Is TRUE with Regard to Sources