Which of the following statements is incorrect?
a. The cystic fibrosis gene is more prevalent amongst U.S. Caucasians of European descent likely as a result of the protection it conferred during a long history of cholera and especially tuberculosis.
b. 1/3 of the male adult global population smokes with a higher concentration of male smokers in the Western Pacific region.
c. The sickle-cell trait provides protection against the parasite responsible for malaria.
d. Polyploidy is important in the production of new species of plants but not animals.
e. Chorionic villus sampling involves removing a sample of fluid from around the fetus and then culturing cells for the determination of chromosomal abnormalities and metabolic disorders.