What is the relationship between population size and the number of generations it takes for an allele to become fixed?

When analyzing tree rings, what do scientists assume a thin ring indicates?

Which of these definitions have been paired with the correct type of cell?

Each member of a class sampled a piece of ptc testing paper. thirty people sampled the chemical. twenty persons were tasters. how many had heterozygous genes? 10 20 0-20 indeterminate