Which statement correctly describes identical twinning?

Which statement correctly describes identical twinning?

• A. Fraternal: two different ova fertilized by two different sperm
• B. Identical: two ova fertilized by two different sperm
• C. Identical: a single zygote splits into two embryos
• D. Fraternal: a single zygote splits into two embryos

Answer: (C)

Identical twinning happens when a single fertilized egg splits into two separate embryos. Since both babies come from the same zygote, they share nearly identical genetic material from both parents. The split can occur at different times in early development, which affects how their placentas and amniotic sacs form, but it doesn’t change the fact that they originate from one zygote. This is why identical twins are genetically the same, unlike fraternal twins, who come from two separate fertilized eggs and can be different in appearance and sex. So, the statement that identifies identical twinning as a single zygote splitting into two embryos is correct.

Identical twinning happens when a single fertilized egg splits into two separate embryos. Since both babies come from the same zygote, they share nearly identical genetic material from both parents. The split can occur at different times in early development, which affects how their placentas and amniotic sacs form, but it doesn’t change the fact that they originate from one zygote. This is why identical twins are genetically the same, unlike fraternal twins, who come from two separate fertilized eggs and can be different in appearance and sex. So, the statement that identifies identical twinning as a single zygote splitting into two embryos is correct.