Question

What are two other terms for dizygotic twins, which make good study subjects because they share many environmental conditions, but only about half of their polymorphisms?

Answer 1

fraternal, non-identical

Dizygotic twins  fraternal or non-identical  share only about half of their polymorphisms. These twins are helpful to study as they tend to share many aspects of their environment. As they are born in the same place, usually within a few minutes of each other, they share many environmental conditions. They had the same in utero environment, they usually have a similar or the same parenting style during their childhood, and a similar or the same education. Similarities during childhood usually occur with wealth, culture, and their community.