_____ share exactly the same genes, and thus any differences between them must be due to environmental factors rather than hereditary differences.
A) Fraternal twins
B) Same-sex siblings
C) Identical twins
D) Same-sex fraternal twins

Question

Quizplus · Accepted Answer

Identical twins share exactly the same genes as they develop from one fertilized egg that splits into two embryos. This makes them genetically identical, whereas fraternal twins (A) develop from two separate eggs fertilized at the same time and therefore do not share all their genes. Same-sex siblings (B) can have the same parents and share some similar genes but are not identical. Same-sex fraternal twins (D) do not exist as fraternal twins are by definition not identical.

_____ Share Exactly the Same Genes, and Thus Any Differences