HHMI BioInteractive: Sickle Cell

A, D He expanded his study area beyond Kenya to the rest of East Africa to see if malaria and sickle disease were connected. He evaluated blood samples for malaria parasites and the presence of sickle cells.

How did Dr. Allison test his hypothesize that sickle cell disease was connected to malaria?

B, C In areas without malaria, individuals with two sickle cell alleles reproduced at lower rates than those without sickle cell disease. In areas with malaria, individuals with one sickle cell allele reproduced at higher rates than thise with no sickle cell alleles.

How does Dr. Allison's work provide and example of natural selection in humans?

B, D The person is homozygous at the hemoglobin locus. The person is susceptible to malaria.

If a person has two normal copies of the hemoglobin allele, which statements are true?

A The sickle cell allele will decrease in frequency.

Predict what will happen to the frequency of the sickle cell allele in areas where malaria has been eradicated.

He hypothesized that there was a connection between malaria and sickle cell disease.

1949, Dr Tony Allison observed a high frequency of Kenyans carrying the sickle cell allele in coastal areas and bear Lake Victoria, but a lower frequency in the highlands. What did he hypothesize?

Sickle cell disease and malaria are both potentially lethal diseases

Compare sickle cell disease and malaria

A Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population.

In some populations, 1 in 500 people have sickle cell disease. What reason does the film give for why a potentially deadly, inherited disease is found at such high frequencies?