What type of twins develop from a single fertilized egg that splits into two?

• A. Fraternal Twins
• B. Identical Twins
• C. Conjoined Twins
• D. Mirror Twins

Answer: (B)

Identical twins develop from a single fertilized egg that splits into two separate embryos. This process occurs during the early stages of cell division, resulting in two genetically identical individuals sharing the same genetic material. Since they come from the same fertilized egg, they also share the same sex and look very similar to each other, though they may have some differences due to environmental factors or individual development.

Fraternal twins, on the other hand, result from two separate eggs being fertilized by two different sperm cells. While they may share some genetic similarities, they are no more genetically alike than any other siblings. Conjoined twins arise when a single fertilized egg does not fully separate, leading to twins that are physically connected. Mirror twins are a type of identical twins where the asymmetrical features might appear mirrored; however, they still originate from the same egg split and are not a separate category in terms of the fertilization process.

Thus, identifying that identical twins come from a single fertilized egg provides clarity on their genetic and developmental similarities.