Sickle-cell anemia is an example of codominance. What implications does this have for people with one or two copies of the sickl
e-cell gene? A. People with two copies of the mutated gene have healthy red blood cells. People with one copy of the mutated gene don't have the disease but are carriers of the disease.
B. People with two copies of the mutated gene have sickle-cell anemia. People with one copy of the mutated gene have both healthy and misshapen red blood cells and are carriers of the disease.
C. People with two copies of the mutated gene are carriers of the disease. People with one copy of the mutated gene don't have the disease.
D. People with two copies of the mutated gene have sickle-cell anemia. People with one copy of the mutated gene have healthy red blood cells.
Answer: B - People with two copies of the mutated gene have sickle-cell anemia. People with one copy of the mutated gene have both healthy and misshapen red blood cells and are carriers of the disease.
Explanation:
Co-dominance is when both the alleles of a gene in a heterozygote show. In the case of sickle cell anemia (since it is a co-dominant trait) even if the person only has one sickle cell allele, symptoms of sickle cell will still show up in that person. That's why the person in this example has both misshapen and healthy red blood cells.
Answer: B - People with two copies of the mutated gene have sickle-cell anemia. People with one copy of the mutated gene have both healthy and misshapen red blood cells and are carriers of the disease.
Flowers and hummingbirds have a mutualistic relationship where both benefit. Flowers produce food in the form of nectar (sugar and water) to attract hummingbirds which, in turn, move pollen for the plant (pollination).
The cell wall is the protective, semi-permeable outer layer of a plant cell. A major function of the cell wall is to give the cell strength and structure, and to filter molecules that pass in and out of the cell.
