Which sex carries gene for twins

It would be difficult to envisage that each antibody is encoded by a separate gene; such an arrangement would require a disproportionate share of the entire human genome. Humans have been growing steadily taller over the centuries as our nutrition and health care improve. As these events are still rare it is difficult to obtain accurate figures. In truth, baldness is a complicated genetic trait that can be inherited by either the mother, the father or both. Adjust slider to filter visible comments by rank. Why does regular trisomy 21 happen? Science still doesn't know exactly what makes some women give birth to identical twins, and others only singles.
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Is it true that having twins runs in families?

Like the first-semester NIPT and nuchal translucency, these blood tests are not definitive. Each chromosome has a long arm and a short arm. There are also long stretches of DNA, the precise role of which is still a mystery. LOL, maybe it was the hormones at the time, but i was furious! At the present time about one baby with Down's syndrome is born for every 1, total births. It is the B lymphocyte population as a whole that produces the tremendous variety of antibodies in humans and other mammals. For translocations involving chromosomes 21 and any other chromosome, the chance of another child with Down's syndrome being born is about one in six if the mother is the carrier and about one in twenty if the father is the carrier.
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Kids' Health - Topics - Sexual reproduction - how babies are made - for kids

As with the other two types of Down's syndrome apart from when a parent is a carrier there is no known reason why mosaic Down's syndrome occurs. Human Fertilisation and Embryology Authority. If X-containing and Y-containing sperm are produced in equal numbers, then according to simple chance one would expect the sex ratio at conception fertilization to be half boys and half girls, or 1: One reason for this is that blood samples can be easily secured and subjected to biochemical analysis without harm or major discomfort to the person being tested. Even if parents do not intend to have more children, knowing that one of them is a carrier can be important for all their children or other relatives. Although genetics have a lot to do with intelligence levels, environment has a lot to do with how those innate smarts actually develop.
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When you register on our site, we will use your information to make sure we are sending you the content that's most helpful to you. Also, because Down's syndrome is present from the time of conception, nothing a woman does in pregnancy will influence whether or not her baby has Down's syndrome. Unfortunately, our editorial approach may not be able to accommodate all contributions. Women of African descent are two times more likely than Caucasian women, and four times more likely than Asian women, to have twins. Many of the serum proteins are polymorphic, occurring as two or more variants with a frequency of not less than 1 percent each in a population. The arrangement of chemicals in the DNA is different for every gene.
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