In Your Textbook, the Lower Frequency of Sickle-Cell Anemia Among

question 21

Multiple Choice

In your textbook, the lower frequency of sickle-cell anemia among present-day Americans of West African ancestry as compared to people living in West Africa blacks is attributed to:

• A)genetic drift.
• B)gene flow.
• C)new mutations.
• D)none of the above

---

Definitions:

Spindle Fibers

The microtubules that form during cell division, helping to separate chromosomes into daughter cells.

Centrioles

Cylinder-shaped organelles found in animal cells, playing a crucial role in cell division by helping in the formation of the spindle apparatus.

Microvilli

Tiny hair-like structures on the surface of cells in the small intestine, increasing surface area for absorption of nutrients.

Columnar Cells

Elongated, pillar-like cells, often found lining organs such as the intestines or respiratory tract, involved in absorption, secretion, or protection.