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 corresponding phenotype can be expressed.
D)Identical twins develop from separate eggs and separate sperm.

Question

Quizplus · Accepted Answer

The chromosomes in the zygote can undergo mutations or recombination during fertilization, resulting in genetic variation from the maternal and paternal genomes.

Answer: D
 Identical twins develop from a single fertilized egg that splits into two, resulting in both individuals having the same genetic makeup. Fraternal twins develop from two separate eggs fertilized by two separate sperm and can have different genetic makeup.

Therefore, choices B and C are false.

Which of the Following Is TRUE with Regard to Sources