Q86 - Applying Mutation-Selection and Heterozygote-Advantage Models to a Recessive Lethal Allele
Indicate in the answer sheet if each of the following statements is true or false.
Using the information and data, determine which of the statements are true or which are false.
A. A completely recessive allele is lethal when homozygous. If the dominant allele mutates to the recessive allele at a rate of 10-6, then the frequency of the lethal allele when the population reaches mutation-selection equilibrium is 0.001.
B. If the frequency of a completely recessive lethal allele is 0.2 and it remains unchanged from generation to generation due to the superior fitness of heterozygotes, then the intensity of selection against the dominant homozygotes should be 0.025.
C. Selection for recessive alleles is less effective than selection against recessive alleles.
D. In a large, randomly mating population, the frequency of an autosomal recessive lethal allele is 0.2. The frequency of this allele in the next generation will be 0.07 if the lethality takes place before reproduction.
Question reproduced from IBO 2016, Theoretical Paper B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)