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.
Best Answer: In most natural ovulation cycles only one egg is released, but of course there twins out there that have been conceived with no medical intervention. Women can release two eggs that are both fertilized or one egg that is fertilized and then split in two.est Answer: In most natural ovulation cycles only one egg is released, but of course there twins out there that have been conceived with no medical intervention. Women can release two eggs that are both fertilized or one egg that is fertilized and then split in two.