The Vitamin D Hypothesis

question 64

Multiple Choice

The vitamin D hypothesis

• A)helps explain why dark-skinned populations are found near the equator.
• B)has never been challenged.
• C)cannot explain why light skin may be adaptive in low UV environments.
• D)remains the primary hypothesis explaining why skin color lightened as populations moved out of Africa.
• E)helped Pasteur to discover the process of homogenization

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Definitions:

SRY Gene

Located on the Y chromosome in males, this gene codes for a transcription factor that binds to regulatory DNA. At about 5 weeks gestation, it turns on genes that start the production of other proteins responsible for the development of gonads into testes.

Zygotes

The initial cell formed when a new organism is conceived, created by the fusion of sperm and egg cells.

XY Chromosome

The combination of chromosomes characterized as male in humans, where a Y chromosome inherited from the father pairs with an X chromosome from the mother.

Distinct Cliques

Social clusters within a community where members share common interests or backgrounds, and distinctly separate from other groups.