Exercises: Hardy-Weinberg Equilibrium
List the five conditions that must be met for a population to remain in Hardy-Weinberg equilibrium. Which of these conditions, if violated, introduces new alleles to a…
List the five conditions that must be met for a population to remain in Hardy-Weinberg equilibrium. Which of these conditions, if violated, introduces new alleles to a population?
In a population at Hardy-Weinberg equilibrium for a gene with two alleles, the frequency of the dominant allele is $p = 0.7$. Use $p + q = 1$ to find $q$, and state what…
In a population at Hardy-Weinberg equilibrium for a gene with two alleles, the frequency of the dominant allele is $p = 0.7$. Use $p + q = 1$ to find $q$, and state what $q$ represents.
In the equation $p^2 + 2pq + q^2 = 1$, state what each term represents (in terms of genotypes). Which term do you use to find the frequency of individuals showing a…
In the equation $p^2 + 2pq + q^2 = 1$, state what each term represents (in terms of genotypes). Which term do you use to find the frequency of individuals showing a fully recessive phenotype?
In a hypothetical population in Hardy-Weinberg equilibrium, a recessive genetic disorder affects 1 in 2,500 people, so $q^2 = 0.0004$. (a) Calculate $q$ and $p$. (b)…
In a hypothetical population in Hardy-Weinberg equilibrium, a recessive genetic disorder affects 1 in 2,500 people, so $q^2 = 0.0004$. (a) Calculate $q$ and $p$. (b) Calculate the frequency of carriers ($2pq$). (c) In a city of 100,000 people, about how many carriers are expected?
A population of 500 snapdragons has 320 red flowers (RR), 160 pink flowers (Rr), and 20 white flowers (rr). (a) Calculate the frequency of the R and r alleles. (b) Use…
A population of 500 snapdragons has 320 red flowers (RR), 160 pink flowers (Rr), and 20 white flowers (rr). (a) Calculate the frequency of the R and r alleles. (b) Use the Hardy-Weinberg equation to find the number of each genotype expected in 500 plants. (c) Decide whether this population appears to be in Hardy-Weinberg equilibrium for this gene, and justify your answer.
In a population assumed to be in Hardy-Weinberg equilibrium, 16% of individuals show a recessive phenotype. (a) Find $q$ and $p$. (b) Find the frequency of…
In a population assumed to be in Hardy-Weinberg equilibrium, 16% of individuals show a recessive phenotype. (a) Find $q$ and $p$. (b) Find the frequency of heterozygotes. (c) Find the frequency of individuals who are homozygous dominant.
A population of 200 lizards has 120 AA, 40 Aa, and 40 aa individuals. (a) Calculate $p$ and $q$. (b) Calculate the genotype counts expected if the population were in…
A population of 200 lizards has 120 AA, 40 Aa, and 40 aa individuals. (a) Calculate $p$ and $q$. (b) Calculate the genotype counts expected if the population were in Hardy-Weinberg equilibrium. (c) Compare observed with expected counts and identify which genotype is over- or underrepresented. (d) Suggest two Hardy-Weinberg conditions that could be violated to explain the pattern, and explain what genotype frequencies you would expect after one generation of random mating.
At birth, a large population is in Hardy-Weinberg equilibrium with $p = 0.6$ and $q = 0.4$ for a gene in which the recessive genotype (aa) is lethal before reproduction.…
At birth, a large population is in Hardy-Weinberg equilibrium with $p = 0.6$ and $q = 0.4$ for a gene in which the recessive genotype (aa) is lethal before reproduction. (a) Calculate the genotype frequencies at birth. (b) After the aa individuals die, calculate the new frequencies of AA and Aa among survivors and the new value of $q$ in the next generation's gametes. (c) Identify which Hardy-Weinberg condition is violated. (d) Explain why $q$ declines slowly over many generations even though all aa individuals are removed every generation.