133k views
5 votes
Sickle cell anemia is a recessive trait (aa) which causes a red blood cell disorder in which there aren't enough healthy red blood cells to carry oxygen to the body. Individuals with the genotype AA have normal red blood cells. Those individuals who are heterozygous for the trait usually have no symptoms of sickle cell disease, but carry the sickle cell trait and can pass it on to their offspring. However, those individuals who carry the sickle cell trait have some protective advantage against malaria, making this a common genotype in malaria prone areas. The graph illustrates the frequencies of two genotypes, AA and Aa, over many generations. Select ALL the conclusions you can draw from the graph provided.

A) There appears to be random mating between genotypes.
B) There is no selective advantage for one genotype over another.
C) This graph probably represents a population in a malaria-prone area.
D) The population reached equilibrium for these traits at about generation 35.
E) Sickle cell disease has died out of this population and will most likely not return.

Sickle cell anemia is a recessive trait (aa) which causes a red blood cell disorder-example-1

2 Answers

5 votes

Final answer:

From the question regarding genotype frequencies and sickle cell anemia in relation to malaria, we can conclude that the heterozygous genotype (Aa) offers a selective advantage in malaria-prone areas and that the population might have reached equilibrium around generation 35. However, diseased genotype (aa) is still a possibility in offspring if both parents are carriers (Aa).

Step-by-step explanation:

In the context of sickle cell anemia and its genetics, the graph referenced in the student's question can lead us to several conclusions regarding the genotypic frequencies over generations:

Option A suggests that there is random mating between genotypes, but without more information on the graph, we cannot confidently draw this conclusion.

Option B is incorrect because the protective advantage against malaria for heterozygous individuals (Aa) indicates there is a selective advantage for this genotype over the homozygous AA and aa genotypes in malaria-prone areas.

Option C is likely correct since the Aa genotype provides a protective advantage against malaria, which would be a factor in maintaining the frequency of this genotype in a malaria-prone area.

Option D suggests the population reached equilibrium for these traits around generation 35; this could be inferred if the frequencies of the genotypes stabilize around this generation.

Option E, which states that sickle cell disease will not return, cannot be concluded because if both parents are carriers (Aa), they can still produce offspring with the disease (aa).

Therefore, c) the graph likely represents a population in a malaria-prone area, and d) the population may have reached equilibrium for these traits at about generation 35. Still, since we don't have the actual graph, the stability of genotype frequencies would need to be verified.

User Wasi Master
by
3.0k points
11 votes

Answer:A is your answer 2020 edg

Step-by-step explanation:

User Nichola
by
3.6k points