2007-09-26 07:52:37 · 17 answers · asked by Eleanor T 3 in Pregnancy & Parenting ➔ Pregnancy
I dont think identical twins can be of mixed gender.They would both have to be the same gender and even then they are not always identical. If its a boy and a girl then they are fraternal twins.
2007-09-26 07:57:38 · answer #1 · answered by happy1187 1 · 3⤊ 2⤋
It very rarely ever happens, there might be a few documented cases in human history. It isn't possible in that identical twins have the exact same genetic makeup. If a pair of twins are a boy and a girl it is probable that they are dizygotic or fraternal twins genetically the exact same thing as regular siblings just born at the same time.
2007-09-26 15:22:59 · answer #2 · answered by lucy diamond 6 · 0⤊ 1⤋
*Identical* twins come from one fertilized egg that then splits. Everything is identical, including the gender. When there is a boy and a girl, they are *fraternal* twins, who come from two separate eggs. Genetically, they are the same as any other siblings. They just happen to be developing at the same time.
2007-09-26 14:57:40 · answer #3 · answered by Tapioca 4 · 0⤊ 2⤋
I saw a program on Discovery Channel or somewhere about identical twins where one lost the Y chromosome just after the split, so one's a normal XY male, and the other's a single X female. She has lots of reproductive sorts of troubles because of only having a single X chromosome.
I thought it could not happen, too, but it turns out it has happened. Three to five cases are documented, according to the website below.
2007-09-26 15:05:23 · answer #4 · answered by ற¢ԲèişŦվ 5 · 4⤊ 0⤋
They can't. Only fraternal twins could be a boy and a girl. Since identical twins share the same DNA it is absolutely impossible for one to be a boy and one to be a girl.
2007-09-26 14:58:41 · answer #5 · answered by ChefMel 5 · 0⤊ 2⤋
Identical twins CAN'T be identical. Identical means the egg splits therefore both babies will be the same gender, but not necessarily look alike.
Boy and girl twins are always called "fraternal."
2007-09-26 14:59:01 · answer #6 · answered by Veritas 7 · 0⤊ 3⤋
Identical twins = one egg that splits, therefore sharing the same DNA = carries the same predisposition to gender as well.
Fraternal twins = two males, two females, or one of each.
2007-09-26 15:11:47 · answer #7 · answered by Impavidsoul 5 · 0⤊ 2⤋
Monozygotic (often referred to as identical twins) can SOMETIMES be of different sexes, but it is VERY VERY rare, and in all of the cases, the female twin has genetic abnormalities and birth defects. For more information, check out this website:
http://www.bellaonline.com/articles/art1291.asp
2007-09-26 15:12:12 · answer #8 · answered by Amanda 6 · 2⤊ 1⤋
They can't. They are identical. Boy and girl twins are fraternal.
2007-09-26 15:01:22 · answer #9 · answered by Anonymous · 0⤊ 2⤋
FRATERNAL TWINS ( THEY LOOK DIFFERENT OR ARE A BOY AND A GIRL) ARE TWO DIFFERENT EGGS THAT ARE RELEASED AND FERTILIZED WHERE AS IDENTICAL TWINS ARE ONE EGG THAT SPLITS IN TO TWO (THEY LOOK THE SAME) THAT IS HOW IT CAN BE THIS WAY
COMING FROM A FRATERNAL TWIN(HAVE A TWIN SISTER 7 MIN OLDER)
2007-09-26 14:58:39 · answer #10 · answered by babymalai 3 · 0⤊ 2⤋