What is the scientific term for identical twins that share 100% of their genetic material?

The term for identical twins that share 100% of their genetic material is monozygotic twins. This terminology derives from the fact that monozygotic twins originate from a single fertilized egg, or zygote, which splits into two embryos. This single egg conception leads to the creation of two individuals with the same genetic blueprint, hence they are known as identical twins.

Dizygotic twins, on the other hand, occur when two separate eggs are fertilized by two different sperm cells, resulting in fraternal twins who share about 50% of their genetic material, similar to regular siblings. Fraternal twins are not genetically identical, thus distinguishing them from monozygotic twins. The term genotypic twins is not a commonly used term in the context of twin studies and does not specifically refer to any type of twin. Therefore, the understanding of monozygotic twins is crucial in genetics and developmental psychology, as it provides insights into the nature versus nurture debate regarding the influence of genetics on behavior and traits.