Bio 20
Dr. Allison tested his hypothesis by (put the steps in order). 1. test for sickle cell disease 2. take blood samples from children in East Africa 3. determine how much of the malaria parasite was in each sample
2, 3,1
Which demographic population has the highest incidence of sickle cell disease?
African Americans
The break through observation that dr. Allison made was that high incidence of sickle cell disease correlated with
High incidence of malaria
Which individuals would be at a disadvantage in an area with high prevalence of malaria?
Homozygous recessive individuals because even though they have some protection against malaria, they have the worst symptoms of sickle cell disease and often die young. Homozygous dominant individuals because they don't have any protection against malaria.
While testing blood samples for sickle cell disease, Dr. Allison determined that there were high frequencies of sickle cell in ______ and low frequencies in the _______.
Moist coastal areas; dry upland areas
Davaun and Skyy Cooper are brother and sister. Both of them have sickle cell anemia. Before the advent of modern medicine, sickle cell anemia almost certainly meant death before adulthood. Even today, young patients can suffer strokes and organ failure. Sickle cell anemia is a genetic disease.
Sickle cell anemia is an example of codominance where both alleles are expressed at the same time. Their parents must be carriers for the disease. Their parents are heterozygous for the disease and the children inherited the copies of the recessive allele from each parent.
Explain "heterozygote advantage" in relation to the sickle-cell gene.
The heterozygote advantage is that it makes the individual immune to malaria.j
Individuals who are heterozygous for sickle cell disease_ (check all that apply)
are carriers for the disease have a resistance to malaria*** usually have few, if any, symptoms of the disease
Dr. Allison found that children who tested positive for sickle cell disease had a
lower malaria parasite count
