High School

Geneticists have discovered that:

A. The genes of any two unrelated persons are 99.9 percent alike.
B. Genetic variation between racial groups is greater than genetic variation within racial groups.
C. There are three "pure" races left on the planet Earth.
D. In Asia and Africa, skin color distinctions are abrupt, not graded as in the United States.

Answer :

Final answer:

Genetic variation is greater within racial groups than between them, contradicting the idea that there are 'pure' races. Skin color distinctions are not abrupt in any part of the world and genetic makeup is far more complex and nuanced.

Explanation:

The subject of these questions is genetics, specifically human genetic variation and race.Genetic variation refers to the differences in DNA sequences between individuals within a population. It's true that the genes of any two unrelated persons are approximately 99.9 percent alike, reflecting our shared evolutionary heritage. However, the idea that genetic variation between racial groups is greater than genetic variation within racial groups is incorrect. Studies have shown the opposite, indicating that there is more genetic diversity within racial groups than between them.

The assertion that there are three 'pure' races left on the planet Earth is not supported by genetic evidence. The concept of 'race' in humans has no consistent biological definition, and genetic diversity is a continuum, not separated into distinct groups. Furthermore, skin color distinctions are not abrupt in Asia and Africa, contrary to the last part of the question. The categorization and significance of skin color varies around the world and is more a social construct than a fixed biological fact.

Learn more about Human Genetics here:

https://brainly.com/question/33711256

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