Q1. Imagine that a sample of the people in your city showed that 1/16 of them cannot roll their tongue. This means that they are homozygous for the recessive gene. Apply the Hardy-Weinberg principle to find out the frequencies of homozygous dominant and heterozygous genotypes in the population.
Q2. What is the phenotypic ratio you would expect to see in the F2 generation if you were following a sex-linked trait? An autosomal trait? Two autosomal dominant characters (dihybrid cross)?