Young Brunette Twin Girls With White Stockings At Home

Zygosity
Zygosity is the degree of identity in the genome of twins. There are five common variations of twinning. The three most common variations are all fraternal (dizygotic):
• Male–female twins are the most common result, 50 percent of fraternal twins and the most common grouping of twins.
• Female–female fraternal twins (sometimes called "sororal twins")