In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the ß hemoglobin alleles in the human gene pool.
What should be the proportion of heterozygous individuals in populations that live here?
A. 0.04
B. 0.16
C. 0.20
D. 0.32
E. 0.80
Answer: D