What type of twins share 100% of their DNA?

• A. Dizygotic twins
• B. Monozygotic twins
• C. Fraternal twins
• D. Identical twins

Answer: (B)

Monozygotic twins, also known as identical twins, originate from a single fertilized egg that splits into two embryos. This splitting results in two genetically identical offspring who share 100% of their DNA. Because they come from the same zygote, their genetic material is the same, which leads to similarities in physical traits, behaviors, and even some psychological characteristics.

In contrast, dizygotic twins (fraternal twins) are the result of two separate eggs being fertilized by two different sperm cells, which means they share, on average, about 50% of their genetic material, similar to regular siblings. Identical twins and monozygotic twins are essentially the same category, with both terms referring to twins that share all of their genetic information. Therefore, the correct identification of the term that specifies twins who share 100% of their DNA is indeed monozygotic twins.