Please back your answer up with facts or a website. Thanks!!!
2006-10-04 08:33:31 · 10 answers · asked by deus82 3 in Science & Mathematics ➔ Biology
OK, please read. I know how twins are formed both mono and di, thats not my question... sorry for the unclear word MY QUESTION IS which parent if any carries the gene which determines that a twin (for arguement's sake: identical twin) will be formed. Please do NOT say neither and that twins are formed by chance because thats NOT TRUE. If twins RUN IN YOUR FAMILY then there has to be a genetic component which makes you more likely to have a twin then a person in which do not run in their family.
2006-10-04 12:13:03 · update #1
Wether an egg forms a twin or not is not dependent on the genetic contribution of either parent. There are a few different ways that twins can form, but they boil down to two categories; monozygotic and dizygotic twins.
In monozygotic twins, a single egg splits into two. This can happen at several different stages of early development, leading to some variable results, but the consequence is effectively the same: two genetically identical children (always will be the same sex).
With dizygotic twins, two separate eggs were released into the uterine tube and both fertilzed. The result here is two gentetically different individuals that are related in the same manner that any two siblings from the same parents are (here they can be different sexes).
Hope that helps!
EDIT: Oh, okay, I misinterpreted your question. A predisposition for twins can occur for some women (women being the key word here, not men). It isn't necessarily a genetic component, though it's not completely understood how the genetics are involved. For instance, women from some ethnic groups are more likely to have twins, wether or not they mate with men from the same group. However, for the most part, the predisposing factors are not genetic, and include things like obesity, age, and wether or not you've been using fertility drugs. As far as I know, there is no contribution from the male that will increase the likelihood of twins.
Because of the great number of people and families out there, you will of course occasionally see some families with more than an average representation of twins (the average being about 1 in 90 births), but that doesn't mean they are genetically predisposed to them; the odds alone mean that there will be families like that in the same manner that the odds mean there will be some families with all boys or all girls.
2006-10-04 08:38:15 · answer #1 · answered by Geoffrey B 4 · 3⤊ 0⤋
What Determines Twins
2016-11-12 04:25:56 · answer #2 · answered by tameka 4 · 0⤊ 0⤋
Actually, it is not a question of which parent, it is more of a question of biochemistry. When the egg is fertilized it goes through the stages of mitotic development sometimes the egg will split into two seperate entities that will carry on through gestation to birth these are identical twins. Whereas two eggs can be fertilized simultaneously and those are termed as fraternal twins. Twins are an inheiritance factor.
2006-10-04 08:51:25 · answer #3 · answered by robert s 5 · 0⤊ 0⤋
NEITHER parent determines if an egg will be a twin. In the case of identical twins, a single egg is fertilized to produce one zygote. That zygote then divides into two seperate embryos. This splitting of the zygote has nothing to do with your genes. It happens randomly. In the case of fraternal twins, two eggs are implanted in the uterus. Each egg is fertilized by a different sperm. Just like in the case of identical twins, this is also random, and neither parent causes it.
2006-10-04 08:39:43 · answer #4 · answered by عبد الله (ドラゴン) 5 · 1⤊ 0⤋
A twin is determined in one of two ways:
1) A fertilized egg splits in half within the first two or three days of fertilization. If this happens, there will be identical twins.
2) A woman's body releases two eggs which are fertilized by two different sperm. If this happens, there will be fraternal twins.
So, essentially, neither parent truly determines a twin. In the case of fraternal twins, there is just an extra egg released, but that's as close as it gets to being determined by the woman.
2006-10-04 08:38:15 · answer #5 · answered by rdnck_grl_ms_007 3 · 2⤊ 0⤋
The woman is the only one with the egg. For identical twins, the egg divides into two. For fraternal twins, there are 2 eggs.
2006-10-04 08:38:54 · answer #6 · answered by Lab 7 · 1⤊ 0⤋
First of all There is only one parent that produces the egg. Twins are genetic. It can be from either parent.
2006-10-04 08:42:41 · answer #7 · answered by Gramms 4 · 1⤊ 0⤋
There are two ways in which twins form. First, the mother may ovulate from both ovaries in one cycle, and the two seperate eggs are both fertilized by seperate sperm. In the second way, one egg is fertilized by one sperm, and that zygote splits into two different people. In both, both parents are "responsible". You need both no matter what.
2006-10-04 08:39:16 · answer #8 · answered by barswhereami 2 · 1⤊ 0⤋
Neither, "an egg" being a twin is the result of the egg breaking apart.
2006-10-04 08:37:48 · answer #9 · answered by Pseudo Obscure 6 · 0⤊ 1⤋
A fraternal twin is 2 eggs. An identical twin is more than one sperm in one egg. If you want proof, do the homework yourself.
2006-10-04 08:55:54 · answer #10 · answered by fairly smart 7 · 0⤊ 2⤋