Choose the true statement.
a. continental crust is less dense than oceanic crust.
b. continental crust is more dense than oceanic crust.
c. continental crust and oceanic crust have the same density.

In a population that is in hardy-weinberg equilibrium, there are two possible alleles for a certain gene, a and a. if the frequency of allele a is 0.4, what fraction of the population is heterozygous? a. 0.40 b. 0.60 c. 0.16 d. 0.48