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Sperm contains either an X(female) chromosome or a Y(male) chromosome, whereas the egg contains only an X(female) chromosome. Neither the egg nor the sperm can be said to have a"sex." The combination of an X-bearing sperm with the (X-bearing) egg produces a female baby. The combination of a Y-bearing sperm with the (X-bearing) egg produces a male baby. It might seem that the man (sperm) that determines the sex of the baby, but this assumes that the egg is passive, accepting the first sperm to arrive at the egg. Some recent evidence indicates that this is not so. See the Wikipedia article on "Maternal influence on sex determination.
Wiki User
∙ 11y ago
Wiki User
∙ 13y agoIt is the egg that determines it. Some families have a predisposition to multiple ovulation (also a factor in IVF) and so more than one egg will become fertilized. Identical twins, however, are from a single egg that splits.
Wiki User
∙ 12y agoThe sperm (from the father) can cay a 'Y' (male) sex gene OR an 'X' (female) sex gene (but not both) so it is the sperm that determines the baby's gender.
The mother's Ovum always has one 'X' (female) sex gene as females are 'XX' and males are 'XY'.
Wiki User
∙ 9y agoThe sperm cell.
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Can twins be two different races?
Of course; identical twins are fertilized from the same sperm and egg, whereas fraternal twins are fertilized from different sperm and egg; thus, fraternal twins would resemble each other no more than regular siblings born at different times.
Why are twins formed in one embryo?
Identical twins are sometimes formed when one egg after being fertilized by one sperm, divides into two halves.
How is a baby sexs determine?
It's determined by the genetic chromosome of the sperm. Women have only one X chromosome in the egg (both egg and sperm have 23 pairs of chromosomes, which unite to form 46). On the other hand, men have either X or Y chromosomes. If an egg (X chromosome) joins with an X chromosome sperm, the result will be a girl. If an egg (X chromosome) joins with a Y chromosome sperm, the result will be a boy. In other words: the guy determines the sex of a baby :)
What determines the sex of the child that develops from the fertilized egg?
It depends on which sex chromosome sperm type fertilized the egg. X for female. Y for male.
Why are some twins identical and some not?
The reason why some twins are identical and some are not starts in utero. Identical twins occur when one egg is fertilized and it splits to create two embryos. Nonidentical twins come from different fertilized eggs.
What is the diffence between identical twins and fraternal twins?
Identical twins come from one egg and one sperm. Fraternal twins come from two eggs and two sperm.
When a sperm meets egg can another sperm meet with the egg?
Yes, and this is one of the ways that you can get twins. The other of course is that the egg divides before the beginning of Mitosis.
Identical twins happen when the two eggs are fertilised?
No. They have to come from the same egg and sperm to have the same DNA (and be identical). Fraternal twins are non identical twins and come from two separate eggs.
Usually one egg is fertilized by one sperm?
because a "wall" is put up when the sperm meets the egg. This prevents another sperm from meeting the egg.
Twins formed by the fertilization of two ova by two sperm are?
They would be fraternal twins. Identical twins are created when one sperm fertilized one egg, and hat egg then splits in two. Identical twins are always the same gender, while fraternal twins can be either gender, or a mix of the two.
How are identical twins genetically from fraternal twins?
Identical twins are genetically the same, because they come from the same fertilized egg/sperm cell zygote, which happens to split into two viable zygotes. Fraternal twins, however, come from two different egg/sperm cell zygotes, that are concurrently fertilized and remain viable.
Can twins be two different races?
Of course; identical twins are fertilized from the same sperm and egg, whereas fraternal twins are fertilized from different sperm and egg; thus, fraternal twins would resemble each other no more than regular siblings born at different times.
How are identical twins created?
One sperm fertilizes one egg, but before the fertilized egg can become a fetus, the egg splits and becomes two eggs made from the same egg and sperm - therefore becoming two babies.
Why can fraternal twins de different sexes while identical twins cannot?
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.
How do you know if you have a girl or a boy?
It depends on women's egg. Women have a egg which is a child. Peroids are eggs, eggs can die if not fertilized, periods drain the egg away. Women grow a egg each month. The egg needs sperm to fertilize to grow into a child. The men's penus touches the women's vagina and the sperm swims into the women's body to find a egg. Only one sperm can get into the egg. The men's sperm decides what gender the baby is. Women's eggs is x. Men's sperm is y and x. If egg x and sperm y touch, it's a boy, if egg x and sperm x touch, it's a girl. If a sperm gets into a egg and the egg breaks in half, it's twins with same gender. If a egg breaks in half before a sperm gets in, then two sperms can get into the two half eggs and thay'll have a different gender, but still twins. So there it is. Please thank me for I'm a guest.
Why are twins formed in one embryo?
Identical twins are sometimes formed when one egg after being fertilized by one sperm, divides into two halves.
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.
