I know that once the sperm enters the egg no other sperm can get in but how our twins concieved is two eggs.
2007-03-05 12:50:57 · 2 answers · asked by Vanessa 2 in Science & Mathematics ➔ Biology
There are two types of twins -- monozygotic (usually called "identical") and dizygotic (called "fraternal"). It sounds like your twins are dizygotic: two of your eggs matured and were released by your Fallopian tubes, then were fertilized by two separate sperm. These fertilized eggs developed into two embryos. Because the twins result from separate pairs of egg and sperm, they will not be identical.
FYI -- monozygotic twins occur when a single zygote (fertilized egg) splits after fertilization. Because the twins come from the same egg and sperm, they will be identical (have the same genetic makeup).
A rare case of monozygotic twins are "polar twins," which occur when a single egg splits in two and the two halves are fertilized by two separate sperm. These twins share identical DNA from the mother, but since the two sperm are different, they will not be identical -- although they will be more genetically similar than fraternal twins.
2007-03-06 00:05:30 · answer #1 · answered by jazzy girl 3 · 0⤊ 1⤋
due to division of fertilized ova into two zygotes giving two embryos
2007-03-05 21:20:26 · answer #2 · answered by the vet 4 · 0⤊ 0⤋