Search results
Results From The WOW.Com Content Network
A vanishing twin, also known as twin resorption, is a fetus in a multigestation pregnancy that dies in utero and is then partially or completely reabsorbed. [ 1 ] [ 2 ] In some instances, the dead twin is compressed into a flattened, parchment-like state known as fetus papyraceus .
The human twin birth rate in the United States rose 76% from 1980 through 2009, from 9.4 to 16.7 twin sets (18.8 to 33.3 twins) per 1,000 births. [5] The Yoruba people have the highest rate of twinning in the world, at 45–50 twin sets (90–100 twins) per 1,000 live births, [6] [7] [8] possibly because of high consumption of a specific type of yam containing a natural phytoestrogen which may ...
The power of twin designs arises from the fact that twins may be either identical (monozygotic (MZ), i.e. developing from a single fertilized egg and therefore sharing all of their polymorphic alleles) or fraternal (dizygotic (DZ), i.e. developing from two fertilized eggs and therefore sharing on average 50% of their alleles, the same level of genetic similarity found in non-twin siblings).
Homopaternal superfecundation is fertilization of two separate ova from the same father, leading to fraternal twins, [3] while heteropaternal superfecundation is a form of atypical twinning where, genetically, the twins are half siblings – sharing the same mother, but with different fathers.
[17] 95% of marmoset fraternal twins trade blood through chorionic fusions, making them hematopoietic chimeras. [ 22 ] [ 23 ] In the budgerigar , due to the many existing plumage colour variations , tetragametic chimeras can be very conspicuous, as the resulting bird will have an obvious split between two colour types – often divided ...
Twins lead different lives despite sharing similar birth times. "We will always have this cosmic wiring and for twins, it is really identical," Tali Edut says. "However, we are human beings with ...
Fraternal twins at two weeks old. The technical term for "fraternal" is "dizygotic" (twins) or "polyzygotic" (triplets or higher order). Fraternal twin sisters taking a nap. Nonidentical twins, the most common kind of multiple birth among humans, occur in about 1 out of every 80 pregnancies.
The word zygosity may also be used to describe the genetic similarity or dissimilarity of twins. [6] Identical twins are monozygotic, meaning that they develop from one zygote that splits and forms two embryos. Fraternal twins are dizygotic because they develop from two separate oocytes (egg cells) that are fertilized by two separate sperm.