Â· 4 years ago. A mutation is a change in the genetic material of an organism. We are made from trillions of cells, each with a nucleus composed of DNA â a set of instructions that tells the cell what to do. Cells copy themselves with astonishing accuracy, but every now and then a piece of code is copied incorrectly.
Identical (or monozygotic) twins happen when a fertilized egg splits into two separate babies-usually within the first twelve days of Mom's pregnancy. After twelve days, the egg may not split entirely and result in conjoined twins.
Fraternal twins form when she releases two (or more) eggs. Each one is fertilized by a separate sperm. Genetically, fraternal twins are no more alike than siblings (brothers and sisters). Identical twins start off as one fertilized egg.o start off, let's first talk about fraternal twins, another word for this is dizygotic which means a fraternal twin happens when two separate eggs are fertilized by two separate sperm. These babies can come out because of different reasons such as hyper-ovulation (it is hereditary).