An online article that your professor asked you to critique states that African Americans cannot contract malaria, even if they go to endemic areas, because of a genetic trait that confers protection from the disease. Your response is that this article is incorrect because .a. african americans have lost the allele for normal red blood cells through genetic drift from their ancestral african population.
b. balanced polymorphism means that not all african americans are heterozygous for the sickle cell trait.
c. protection from malaria cannot be conferred by genes.
d. african americans are more likely to have thalassemia, which does not protect a person completely from contracting malaria.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.  

b.have there own function.