answersLogoWhite

0


Best Answer

To keep it simple and not get too technical, fraternal twins are from two eggs and two sperm that independently combine to produce a baby. Identical twins come from a single egg and sperm that divide to create two separate children. Gender is controlled by the males sperm and whether it contains the male genetic X chromosome. Since identical twins have the same sperm their genetic makeup is exactly the same (same egg and sperm used in development). Fraternal twins have two separate sperm and therefore it is possible one has the X chromosome and other does not.

User Avatar

Wiki User

9y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Why can fraternal twins de different sexes while identical twins cannot?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Are paternal twins identical?

I dont think there is such a thing as paternal twins...perhaps you are thinking of fraternal twins. In that case, they are not identical twins, they do not look the same and they can be different sexes.


Twins who have different sexes are called?

fraternal


What is the difference btween identical twins and fraternal twins?

Identical twins are the result of a single fertilized embryo splitting in two at an early stage and forming two viable embryos. As such, identical twins have identical DNA. Fraternal twins are the result of two distinct fertilized embryos being viable. As such, they have different DNA. They could even be different sexes.


Was Shakespeare's twins identical?

No. All identical twins are the same sex. Judith and Hamnet were opposite sexes, and so were fraternal twins.


Can identical twins be of different sexes?

They can be. While identical twins always have to be the same gender, fraternal twins usually are not. However this is not always the case. Identical twins occur because they inhabit the same egg. Fraternal twins because two eggs were fertilized at the same time. So fraternal twins could be the same gender, but usually they are of the opposite gender.


How do twins look exactly alike?

They do look different! Even identical twins, with identical DNA, are different. Most have a slight difference in height and weight. Many people have a difficult time telling them apart because they are focusing on the wrong things. If someone looks only at the hair, they may not see that their faces are slightly different.


Are fraternal twins never the same sex?

Fraternal twins can be the same sex or opposite sexes. It doesn't matter.


Are identical twins developed from one egg or two?

There are at least three ways to produce twins. One is when the female produces two eggs, both of which are fertilized by the male. This is how fraternal twins are produced. Fraternal twins can be both the same sex or different sexes. Fraternal twins may only bear a slight resemblance to one another, no more than any two siblings might. (Fraternal twins can actually have different biological fathers, because the eggs may be produced a day or two apart.) Another is for the woman to produce one egg which is fertilized by the male, and then the egg divides into two. This is the traditional way that so-called identical twins are produced. Identical twins are always the same sex. (I use the term 'so-called,' because they are actually 'mirror image' twins.) A third way is for the woman to produce one egg, which then divides into two, which are both subsequently fertilized. There is a greater chance that such twins will resemble one another than fraternal twins, and they may be the same or opposite sexes.


How do you get identical twins and fraternal twins?

Identical twins are two children born of one egg and one sperm, that splits early on and then separates, each half then developing into a full organism. Since they came from only one egg and one sperm, their genes will be identical. Fraternal twins are two children born of two eggs and two sperms, each of them developing into a full organism. Since they did not come from only one egg and one sperm, their genes will be different. They could even be opposite sexes.


What is the different between identical twins and franternal twins?

The DNA of identical twins and of clones is, apart from random, environmentally produced mutations, 100% identical. The only difference is that clones are produced on purpose through advanced bioengineering techniques while identical twins happen as an accident of nature. Identical twins are, in a sense, natural clones.


How are identical and non-identical twins produced?

When an egg is fertilized by a sperm, it becomes a zygote. That zygote goes through cell division to become an embryo.Sometimes, the zygote splits and becomes two separate organisms - they will be identical twins. If the zygote splits and separates multiple times, you can get triplets or even quadruplets. They will all be (more-or-less) genetically identical.If two eggs are released during ovulation and each one is fertilized (by a separate sperm) then you will have fraternal (non-identical) twins. Again, if multiple eggs are released (for example, when a woman is undergoing fertility treatments) and each one is fertilized by a separate sperm, you can get triplets, quadruplets, etc. They will all be genetically different and can even be different sexes.


Do fraternal twins look alike?

Usually but not always. They can even be different sexes. Identical twins are fromed from one fertilized egg which splits into two and so genetically they have the same DNA and are therefore identical. Fraternal twins are formed from two separate eggs fertilized by two separate sperm cells, and are called 'twins' simply because they share the womb during their development. Otherwise, they are no more similar than normal brothers, sisters or a brother and sister.