Except identical twins why aren't any two human beings identical to each other?
Answers
The medical name for identical twins is monozygotic twins. Mono means one and zygote means a cell that's formed by an egg plus a sperm—so identical twins are created when a single zygote splits into two. As the two zygotes travel to the uterus, they each continue to divide and grow. Scientists don't know what causes a single zygote to separate into two individual ones. Technically it's considered a malfunction of the normal development process.
The two separate beings who are created in this way share the same DNA, which stands for deoxyribonucleic acid. DNA is made up of the chromosomes that contain the genetic information that determines everything about us—from the color of our hair and eyes to our athletic ability and personality traits.
Even though identical twins share the same DNA, they aren't necessarily exactly alike. Environmental factors can influence a person's physical appearance, for example, and epigenetic factors create differences as twins age. The epigenome describes chemical changes within DNA as an organism ages. These factors explain why identical twins can be different, whether in appearance, temperament, or personality.