Different Types of Twins

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“It’s double the giggles and double the grins, and double the trouble if your blessed with twins”- Unknown. Parents of same sex twins always wonder if they have identical or fraternal twins. Without a DNA test there is no absolute way to tell. Unique and unusual, twins are like snowflakes, no two are alike. Identical and Fraternal these are the types of twins most people are familiar with, and then there are Half-twins.

Identical twins which are also known as monozygotic; occur when a single egg is fertilized to form one zygote, which divides to then turn into two separate embryos. Some identical twins share the same placenta. However, they usually grow within separate amniotic sacs in the uterus. Identical twins are almost always the same sex, but surprisingly there are a tiny number of boy girl monozygotic twins and they usually share the same blood type; the only way to be sure whether the twins are truly identical, is to take a genetic test to see the overlap of the DNA. Some other famous identical twins include football players Ronde and Tiki Barber and musicians Joel and Benjii from Good Charlotte. Identical twins are as close as nature can get to human cloning. Some are amazingly mirror images; their movements can be perfectly in-sync. Others can be separated for years only to discover they share similar; jobs, taste and hobbies, but not all Identical twins are as identical as scientist once thought. Advances in Genetic sciences are revealing differences in; personality, developmental, diseases and sexuality. They may look alike but we know they’re already different.

Fraternal twins are known as Dizygotic; usually occurring when two fertilized eggs are implanted in the uterine wall at the same time, but the two eggs are independently fertilized by two different sperm cells. Fraternal twins can also have two different fathers which are called heteropaternal superfecundation. Fraternal fetuses have separate placentas and...
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