what gender is more common in twins?
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For example, the sex ratio of birth in the US is 1.05 males/female, while it is 1.07 males/female in Italy. However, males are also more susceptible than females to die in utero, and since the death rate in utero is higher for twins, it leads to female twins being more common than male twins.
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Boy/girl twins are always fraternal or (dizygotic); they can only form from two separate eggs that are fertilized by two separate sperm. The terms identical and fraternal don't describe what the twins look like, but actually how they form.
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In about 21% of identical (monozygotic or MZ) twin pairs, one twin is right-handed and the other is either left-handed or ambidextrous. Since identical twins share identical genes, this is evidence that handedness is not a totally genetic trait.
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Identical twins share all of their genes and are always of the same sex. In contrast, fraternal, or dizygotic, twins result from the fertilization of two separate eggs during the same pregnancy. They share half of their genes, just like any other siblings.
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No! In about 21% of identical (monozygotic or MZ) twin pairs, one twin is right-handed and the other is either left-handed or ambidextrous. Since identical twins share identical genes, this is evidence that handedness is not a totally genetic trait.
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They Can Be Different Genders or the Same Because fraternal twins originate from separate conceptions, they can be boys, girls, or one of each (just like a singleton baby).
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Identical twins generally have the same sex, eye and hair color, as well as blood type. Their physical features look typically the same, with most twins having an exact mirror face of the other.
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Marilyn: If a woman has twins, what are the chances that the babies will be of the same or the opposite sex? I contend they're 25 percent for two boys, 25 percent for two girls and 50 percent for one boy and one girl. My friend says it's 33.3 percent for each of the possibilities.
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These twins can be the same or different sexes and are no more alike than any brother or sister, despite being born together. In this case of semi-identical, or sesquizygotic, twins, the egg is thought to have been fertilised simultaneously by two sperm before it divided.
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Can male/female twins ever be identical? In 99.9% of cases boy/girl twins are non-identical. However, in some extremely rare cases resulting from a genetic mutation, identical twins from an egg and sperm which began as male (XY) can develop into a male / female pair.
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Identical twins are also known as monozygotic twins. They result from the fertilization of a single egg that splits in two. Identical twins share all of their genes and are always of the same sex.
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Boy/girl twins are always fraternal or (dizygotic); they can only form from two separate eggs that are fertilized by two separate sperm. ... Identical (monozygotic) twins are always of the same sex because they form from a single zygote (fertilized egg) that contains either male (XY) or female (XX) sex chromosomes.
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As fraternal twins originate from separate conceptions, they can either be all boys, girls, or one of each. ... Usually, the chances of fraternal twins being boys, girls, or a combination of both are the same as for any normal babies. Identical twins (Monozygotic), on the other hand, are always of the same gender.
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Sometimes health care professionals identify same-sex twins as fraternal or identical based on ultrasound findings or by examining the membranes at the time of delivery. The best way to determine if twins are identical or fraternal is by examining each child's DNA.
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In 99.9% of cases boy/girl twins are non-identical. However, in some extremely rare cases resulting from a genetic mutation, identical twins from an egg and sperm which began as male (XY) can develop into a male / female pair.
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This differs from fraternal twins, where two eggs (ova) are fertilised by two sperm and produce two genetically unique children, who are no more alike than individual siblings born at different times. Twins are more or less equally likely to be female or male.
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The chances of having identical twins is relatively rare — around 3 or 4 in every 1,000 births. And while it may be obvious, identical twins are always the same sex, either both boys or both girls, at birth.