What differentiates whether twins will be fraternal or identical?

Question

Can someone give me the biological details of this?

Answer 1

Wow what timing. Scientists have now discovered that there are 3 different types of twins. This news article gives great background about all three.

Answer 2

Quite simply, identical twins are the result of a single egg being fertilized by a single sperm. The single fertilized egg then divides into two separate embryos that go on to become identical twins.

Fraternal twins are the result of two separate eggs being ovulated at the same time. In this instance, two different sperm are responsible for fertilizing the two eggs.

One way to think of this is that fraternal twins are really just like any other siblings except for the fact that they happened to be conceived at the same time. They are as likely or unlikely to look like each other as any other siblings. Identical twins, however, generally look more alike, having originated from the same egg.

Answer 3

Identical twins come from one egg that splits into 2 fetus. They are the same sex and DNA is the same. Fraternal twins are from 2 different eggs fertilized at the same time. They can be same sex or boy/girl.

See Yahoo news for new discovery of Identical/fraternal twins. Didn't read article, but something new has been discovered just recently

Answer 4

fleur actually, as we all know there two kinds of twins, fraternal and identical..
Human twins are two individuals who have shared the uterus during a single pregnancy and are usually, but not necessarily, born in close succession. Due to the limited size of the mother's womb, multiple pregnancies are much less likely to carry to full term than singleton births, with twin pregnancies lasting only 37 weeks on average, 3 weeks less than full term. Since premature births can have health consequences for the babies, twin births are often handled with special precautions.



well fraternal actually twins form when two separate eggs are fertilized by separate sperm. Fraternal twins are no more genetically similar than siblings born apart. Tha is why they are not having same physical appearance.

while Identical twins occur when a single egg is fertilised to form one zygote (monozygotic) which then divides into two separate embryos. Although their traits and physical appearances are not exactly the same due to environmental conditions in both the womb and outside the womb, they do have the same DNA. that's is why mostly they have same physical apperances.

Answer 5

Identical twins come from the same egg which divides into 2. Fraternal come from 2 separate eggs fertilised at about the same time.

Answer 6

Fraternal twins can be both girls, both boys or one of each. They are created from two eggs, and two sperm, and will share no more characteristics than regular siblings.
Identical twins come from one egg and one sperm which when the cells divide, the split into two embryos. They will either both be girls, or both boys.
Siamese or co-joined twins are identical twins that have not fully separated.

Answer 7

According the biological maybe almost same but the habitual is different. Twins are unique, they can feel each other if the one get different thing.

Answer 8

identical twins are born when one egg is fertilized, and splits into two .(when it doesnt split completely, you get siamese twins).. fraternal twins are born when two eggs are fertilised with two different sperm cells.

Answer 9

Identical twins are two babies in ONE egg.
Fraternal twins are two babies, one each in TWO different eggs.

If you're expecting twins, GOOD LUCK! It's a lot of work, but they are also a blast!

Answer 10

if there are two separate eggs they are fraternal and they are always different sexes(boy and girl) identical are from the same egg and really look alike .they are the same sexes