Solved by a verified expert:1. Suppose a gene has two alleles, one of which is dominant over the other. Anindividual whose genotype is homozygous for the dominant allele has which of thefollowing?a. Two copies of the allele that determines phenotype whenever the allele is presentb. Two copies of the allele whose effect is hidden unless the other allele is absentc. One copy of the allele that determines phenotype when present and one copy of the otheralleled. One copy of each of two alleles that both contribute equally to determining phenotypeUse the following information for the next 2 questions.Pigeons have two alleles of a single gene that determines whether they have feathers on theirlower legs. The alleles are called no grouse (associated with the featherless phenotype)and grouse (associated with feathery legs).2. Suppose a pigeon that is homozygous for the no grouse allele mates with aheterozygous pigeon. What is the expected frequency of the homozygous no grouseGENOTYPE in the offspring?a.b.c.d.0%50%75%100%3. The no grouse allele is dominant over the grouse allele. If a pigeon homozygous forthe no grouse allele mates with a heterozygous pigeon, what is the expectedfrequency of the feathery-legged (grouse) PHENOTYPE in the offspring?a.b.c.d.0%50%75%100%4. In a certain species of flowering plant, the allele for white petal color is dominantand the allele for red petal color is recessive. If you mated a homozygous red flowerwith a homozygous white flower, what would you expect the offspring to look like?a. All offspring will have red petals.b. All offspring will have pink petals.c. All offspring will have white petals.d. Half of the offspring will have red petals and the other half will have white petals.5. A scientist came across two populations of beetle species,each pure-breeding. One population was all red in color; the otherwas all black. The scientist mated one red beetle with one blackbeetle, and the offspring were all black. What is the dominancerelationship between the two alleles?a.b.c.d.Black is dominant over red.Red is dominant over black.Black and red are codominant.More crosses are needed to determine the dominance relationship.6.Imagine a species whose eye color is determined by a receptormolecule called EyeC. When EyeC is not activated, cAMP levels inthe cell are low and yellow pigment is produced. When EyeC isactivated by the binding of a signal molecule, cAMP levels riseand blue pigment is produced.The P allele codes for a version of EyeC that responds to signalmolecules and therefore turns on and off, resulting in green eyecolor (from both blue and yellow pigment). The Qallele codes fora version of EyeC that is always activated, even when signalmolecules are not present.Assuming EyeC functions similarly to MC1R, which of thefollowing statements is the best prediction of the dominancerelationship between alleles P and Q as well as the phenotypefor PQ individuals?a.b.c.d.Q is dominant over P, and the eye color of PQ individuals is blue.Q is dominant over P, and the eye color of PQ individuals is yellow.P is dominant over Q, and the eye color of PQ individuals is blue.P and Q are codominant, and the eye color of PQ individuals is green.7. A large sunflower population is established in a field. The flowersmate randomly, and all individuals are equally likely to surviveand reproduce. In this population, 60% of the alleles of a gene forpetal color are dominant and 40% of the alleles are recessive.Given this information, after many generations, which of thefollowing options would be most likely?a.b.c.d.The allele frequencies will be 100% dominant and 0% recessive.The allele frequencies will be 80% dominant and 20% recessive.The allele frequencies will be 60% dominant and 40% recessive.There is no way to predict what the allele frequencies will be.8. A lizard population has two alleles for horn length. Long hornshelp protect the lizard from predation by birds. Homozygoteswith allele 1 have long horns, while homozygotes withallele 2 have short horns. Given this information, which of thefollowing is most likely true about the mode of inheritance forallele 1, and why?a.b.c.d.Allele 1 is dominant, because it gives lizards an advantage.Allele 1 is recessive, because it gives lizards an advantage.Alleles 1 and 2 are codominant, because each codes for a different horn length.It is impossible to say, because dominance cannot be inferred from fitness.9. The allele for black noses in wolves is dominant over the allele forbrown noses. There is no known selective advantage for one nosecolor over another in wolves. If this remains true, which of thefollowing statements is most likely TRUE about the change in wolfnose colors over many generations?a.b.c.d.Black noses will become more common than they are now.Black noses will stay about the same frequency as now.Black noses will become less common than they are now.Brown noses will disappear after enough generations pass.10. A large population of land turtles on an isolated island has twoalleles for a gene that determines shell thickness. The allele forthinner shells is dominant over the allele for thicker shells. Thethinner-shell allele occurs at a frequency of 20%. Assuming thereis no net advantage to thick or thin shells, what should thefrequency of homozygous thicker-shelled turtles be in thepopulation? (Hint: Use a large Punnett square to calculate theanswer.)a.b.c.d.4%16%50%64%
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