A fruit fly population has a gene with two alleles, A1 and A2. Tests show that 70% of the gametes produced in the population contain the A1 allele. If the population is in Hardy-Weinberg equilibrium, what proportion of the flies carry both A1 and A2?
A) 0.7
B) 0.49
C) 0.21
D) 0.42
E) 0.09
Answer: D