Artificial embryo twinning is a method of making clones that mimics the natural process of creating identical twins, according to the Genetic Science Learning Center. It uses the same approach as natural cloning, but it ... More »

Cloning can be done by a variety of methods including natural methods such as asexual reproduction and artificial methods by cloning genes, cells or entire organisms. When a biological entity is cloned, a genetically ide... More » Science Biology Molecular Biology & DNA

Identical twins have the same DNA code because they are the result of an embryo splitting in half. Fraternal twins do not share the same DNA because they are a result of two separate embryos. More » Science Biology Molecular Biology & DNA

The National Institutes of Health defines therapeutic cloning as cloning an embryo only for the purpose of producing embryonic stem cells with the same DNA as the donor cell. Therapeutic cloning aims to create stem cells... More » Science Biology

After fertilization, the cells in the zygote divide rapidly to form a morula, which becomes the embryo after approximately five days. The fetus is present about eight weeks after the fertilization takes place. More »

The first cows were cloned by separating one cell from a developing cow embryo and, using electricity, fusing it to a donor cell. The cow embryo cell had the nucleus, which contains DNA. When the fused cell started divid... More » Science Biology

Fraternal twins, also known as dizygotic twins, occur when two separate eggs are fertilized by two separate sperm. This results in two babies who are not identical and who do not come from the same egg. Fraternal twins c... More »