What is the meaning of selectively permeable? a) some molecules can pass, some are blocked. b) molecules can pass, but objects are blocked. c) all harmful molecules are blocked. d) all molecules are blocked except for water.

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