GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Sickle cell anemia makes you immune to Malaria.
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Malaria and sickle cell occur throughout the same areas only in Africa but not in the United states.
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Malaria provides a strong resistance against sickle cell disease.
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Sickle cell anemia provides an advantage in resistance against Malaria which is common in Africa (Malaria) but not in the United states.
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Detailed explanation-1: -This is because SCD and SCT are an evolutionary trait that people developed in response to help protect them from malaria. As such, this condition is common in large parts of Africa. Symptoms often begin within the first few months of life, but respond well to early, effective treatments.
Detailed explanation-2: -There are many genes that influence just this. For example, a genetic variance causing sickle cell anemia actually protects against another disease, malaria. This explains why the gene for sickle cell anemia is found in about 7% of the population in malaria-stricken regions, but is virtually nonexistent elsewhere.
Detailed explanation-3: -More than 75% of the global burden of SCA occurs in sub-Saharan Africa, 8 where scarce health resources and inadequate awareness among health care providers and the general public contribute to shocking rates of early mortality.
Detailed explanation-4: -It turns out that, in these areas, HbS carriers have been naturally selected, because the trait confers some resistance to malaria. Their red blood cells, containing some abnormal hemoglobin, tend to sickle when they are infected by the malaria parasite.