Identical twins look the same and may be very difficult to tell apart. Identical twins are always the same sex-either two boys or two girls. How Identical twins form??? an egg has been realesed from the ovary and is fertilized by a single sperm.the fertilized egg divides for the first time. the two cells it produces , unusually, separate. Each cell then developes into a fetus. because each cell contains identical genetic information, the two fwtus are identical.
fraternal twins are the same age but otherwise look just like any other brothers or sisters. Fraternal twins may be the same sex or different sexes. How Fraternal Twins are formed??? two eggs are realesed at the same time from one or both ovaries. Each egg is fertilized by a different sperm. The two fertilized eggs contain different genetic information. because of this the two twins ate not identical.
From: "Under The Microscope, Making Life, How We Reproduce and Grow." Richard Walker
