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.
The main cause of fraternal and identical twins comes from conception; either two completely separate eggs can be fertilized (fraternal twins) or one fertilized egg can split into two during maturation (identical twins).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).