Use the Following Information to Answer the Question Below

question 25

Multiple Choice

Use the following information to answer the question below.
In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool.
In the United States, the parasite that causes malaria is not present, but it is present in African-Americans whose ancestors were from equatorial Africa. What should be happening to the sickle-cell allele in the United States, and what should be happening to it in equatorial Africa?

• A) stabilizing selection; disruptive selection
• B) disruptive selection; stabilizing selection
• C) directional selection; disruptive selection
• D) directional selection; stabilizing selection

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Definitions:

Red Algal Ancestor

The ancient progenitor of current red algae species, suggesting a common lineage from which modern red algae have evolved.

Land Plants

Organisms that are part of the kingdom Plantae, characterized by their ability to perform photosynthesis and live predominantly on land.

Causal Organism

A pathogen or microorganism that causes disease or illness in its host.

Protozoa

An informal group of unicellular, animal-like protists, including amoebas, foraminiferans, actinopods, ciliates, flagellates, and apicomplexans. (The adjectival form is protozoan.)