Question: A plant breeder has a tall stemmed garden pea plant. How can he determine if it is homozygous or …
Show transcribed image text A plant breeder has a tall stemmed garden pea plant. How can he determine if it is homozygous or heterozygous? Solution: Offspring that show the dominant character (for example, tall stems in garden peas) are alike phenotypically but may be either heterozygous (Tt) or homozygous (TT) for that character. To determine their genotype, the test cross or backcross is used, crossing the dominant phenotype individual of unknown genotype with a pure recessive individual. If the tall plant under test is homozygous (TT), all of the offspring from a backcross with the recessive (tt) will be tall (Tt); if. however, it is heterozygous (Tt), the offspring will be equally tall and short. Working backward, complete the Punnett squares below by determining parent genotypes from offspring genotypes. The identification of homozygous dominant individuals is of utmost importance to an animal or plant breeder who is trying to establish true-breeding strains of animals or plants. Problem 2: An animal breeder wants to know if a black guinea pig is homozygous or heterozygous for coat color. He test crosses the black guinea pig with a homozygous recessive white guinea pig. If one of the offspring is white, what is the genotype of the black guinea pig? Construct a Punnett square to show your calculations. Problem 3: In guinea pigs, black is dominant over white. A black guinea pig is mated with a white one. If, over several years, the pair has 50 black offspring and no whire, what is the probable genotype of the black guinea pig? Show your calculations in the space below.
A plant breeder has a tall stemmed garden pea plant. How can he determine if it is homozygous or heterozygous? Solution: Offspring that show the dominant character (for example, tall stems in garden peas) are alike phenotypically but may be either heterozygous (Tt) or homozygous (TT) for that character. To determine their genotype, the test cross or backcross is used, crossing the dominant phenotype individual of unknown genotype with a pure recessive individual. If the tall plant under test is homozygous (TT), all of the offspring from a backcross with the recessive (tt) will be tall (Tt); if. however, it is heterozygous (Tt), the offspring will be equally tall and short. Working backward, complete the Punnett squares below by determining parent genotypes from offspring genotypes. The identification of homozygous dominant individuals is of utmost importance to an animal or plant breeder who is trying to establish true-breeding strains of animals or plants. Problem 2: An animal breeder wants to know if a black guinea pig is homozygous or heterozygous for coat color. He test crosses the black guinea pig with a homozygous recessive white guinea pig. If one of the offspring is white, what is the genotype of the black guinea pig? Construct a Punnett square to show your calculations. Problem 3: In guinea pigs, black is dominant over white. A black guinea pig is mated with a white one. If, over several years, the pair has 50 black offspring and no whire, what is the probable genotype of the black guinea pig? Show your calculations in the space below.
