Genetics Practice Genetics Practice Open Book QuizOpen Book Quiz

In dogs, wire hair (H) is In dogs, wire hair (H) is dominantdominant to to smooth (h). In a cross of a smooth (h). In a cross of a homozygoushomozygous wire-haired dog with a smooth-haired wire-haired dog with a smooth-haired dog, what will be the dog, what will be the phenotypephenotype of the of the F1 generationF1 generation? ?

Woodrats are medium sized rodents with Woodrats are medium sized rodents with lots of interesting behaviors. You may lots of interesting behaviors. You may know of them as packrats. Let's assume know of them as packrats. Let's assume that the trait of bringing home shiny that the trait of bringing home shiny objects (H) is controlled by a single objects (H) is controlled by a single locuslocus gene and is gene and is dominantdominant to the trait of to the trait of carrying home only dull objects (h). carrying home only dull objects (h). Suppose two Suppose two heterozygousheterozygous individuals individuals are crossed. How many of each are crossed. How many of each genotype genotype would be expected?would be expected?

Saguaro cacti are very tall cylindrical plants Saguaro cacti are very tall cylindrical plants that usually have two L-shaped arms, one on that usually have two L-shaped arms, one on each side. Suppose you lived in southern each side. Suppose you lived in southern Arizona where the Saguaro cactus is common Arizona where the Saguaro cactus is common and you happen to have one growing in your and you happen to have one growing in your yard. Your Saguaro has two arms but one is yard. Your Saguaro has two arms but one is longer than the other. Now, assume that arm longer than the other. Now, assume that arm length in these cacti are controlled by a single length in these cacti are controlled by a single genegene with arms of the same length (A) being with arms of the same length (A) being dominantdominant to arms of different lengths. What is to arms of different lengths. What is the the genotypegenotype of your cactus? of your cactus?    

The common grackle is a species of robin-The common grackle is a species of robin-sized blackbirds that are fairly common (hence sized blackbirds that are fairly common (hence the name) over most of the United States. the name) over most of the United States. Suppose that long tails (L) were Suppose that long tails (L) were dominantdominant to to short tails in these birds. A female short-tailed short tails in these birds. A female short-tailed grackle mates with a male long-tailed grackle grackle mates with a male long-tailed grackle who had one parent with a long tail and one who had one parent with a long tail and one parent with a short tail. What is the male's parent with a short tail. What is the male's genotypegenotype? ? How many of each How many of each genotypegenotype will be found in will be found in the the F1 generationF1 generation??

About 70% of Americans perceive a bitter taste About 70% of Americans perceive a bitter taste from the chemical phenylthiocarbamide (PTC). from the chemical phenylthiocarbamide (PTC). The ability to taste this chemical results from a The ability to taste this chemical results from a dominantdominant allele (T) and not being able to taste allele (T) and not being able to taste PTC is the result of having two PTC is the result of having two recessiverecessive alleles (t). Albinism is also a single alleles (t). Albinism is also a single locuslocus trait trait with normal pigment being with normal pigment being dominantdominant (A) and (A) and the lack of pigment being the lack of pigment being recessiverecessive (a). A (a). A normally pigmented woman who cannot taste normally pigmented woman who cannot taste PTC has a father who is an albino taster. She PTC has a father who is an albino taster. She marries a marries a homozygoushomozygous, normally pigmented , normally pigmented man who is a taster but who has a mother that man who is a taster but who has a mother that does not taste PTC. What are the does not taste PTC. What are the genotypesgenotypes of of the possible children the possible children

Wolves are sometimes observed to have black Wolves are sometimes observed to have black coats and blue eyes. Assume that these traits coats and blue eyes. Assume that these traits are controlled by single are controlled by single locuslocus genes and are genes and are located on different located on different chromosomeschromosomes. Assume . Assume further that normal coat color (N) is further that normal coat color (N) is dominantdominant to to black (n) and brown eyes (B) are dominant to black (n) and brown eyes (B) are dominant to blue (b). Suppose the alpha male and alpha blue (b). Suppose the alpha male and alpha female of a pack (these are the dominant female of a pack (these are the dominant individuals who do most of the breeding) are individuals who do most of the breeding) are black with blue eyes and normal colored with black with blue eyes and normal colored with brown eyes, respectively. The female is also brown eyes, respectively. The female is also heterozygousheterozygous for both traits. What are the for both traits. What are the percentages of each genotype? The ratio?percentages of each genotype? The ratio?

The lubber grasshopper is a very large The lubber grasshopper is a very large grasshopper, and is black with red and grasshopper, and is black with red and yellow stripes. Assume that red stripes yellow stripes. Assume that red stripes are expressed from the are expressed from the homozygoushomozygous RR RR genotypegenotype, yellow stripes from the , yellow stripes from the homozygous rr genotype, and both from homozygous rr genotype, and both from the the heterozygousheterozygous genotype. What will be genotype. What will be the the phenotypic ratiophenotypic ratio of the of the F1 generationF1 generation resulting from a cross of two resulting from a cross of two grasshoppers, both with red and yellow grasshoppers, both with red and yellow stripes (incomplete dominance)stripes (incomplete dominance)

A naturalist visiting an island in the middle of a A naturalist visiting an island in the middle of a large lake observes a species of small bird with large lake observes a species of small bird with three distinct types of beaks. Those with short, three distinct types of beaks. Those with short, crushing beaks (BB) consume hard shelled crushing beaks (BB) consume hard shelled nuts, those with long, delicate beaks (bb) pick nuts, those with long, delicate beaks (bb) pick the seeds from pine cones, and those with the seeds from pine cones, and those with intermediate beaks (Bb), consume both types intermediate beaks (Bb), consume both types of seeds though they are not as good at either. of seeds though they are not as good at either. Assume that this difference in beak Assume that this difference in beak morphology is the result of incomplete morphology is the result of incomplete dominance in a single locus gene. Which of the dominance in a single locus gene. Which of the mated pairs below will have the best adapted mated pairs below will have the best adapted offspring in a year in which most of the food offspring in a year in which most of the food available is in the form of hard shelled nuts? available is in the form of hard shelled nuts?

The bison herd on Konza Prairie has begun to The bison herd on Konza Prairie has begun to show a genetic defect. Some of the males have show a genetic defect. Some of the males have a condition known as "rabbit hock" in which the a condition known as "rabbit hock" in which the knee of the back leg is malformed slightly. We knee of the back leg is malformed slightly. We do not yet know the genes controlling this trait do not yet know the genes controlling this trait but for the sake of our question, we shall but for the sake of our question, we shall assume it is a sex-linked gene and that it is assume it is a sex-linked gene and that it is recessive. Now, suppose that the herd bull (the recessive. Now, suppose that the herd bull (the dominant one which does most of the dominant one which does most of the breeding) who is normal (XN) mates with a cow breeding) who is normal (XN) mates with a cow that is a carrier for rabbit hock. What are his that is a carrier for rabbit hock. What are his chances of producing a normal son? (sex chances of producing a normal son? (sex linked)linked)