Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download Biology I - Genetic Problems
Document related concepts
Transcript
Problems Involving One Trait 1. Give the genotype and phenotype of the following individuals: Genotype Phenotype E = Free ear lobes a. Homozygous recessive ________ ____________ e = attached ear lobes b. Heterozygous ________ ____________ c. Homozygous dominant ________ ____________ ************************************************ R = Right handed a. Homozygous dominant ________ ____________ r = left handed b. Homozygous recessive ________ ____________ c. Heterozygous ________ ____________ ************************************************ 2. Let: B = Brown fur b = silver-blu fur On a Punnett square, show the predicted results of a cross between a homozygous Brown mink with a silverblu female mink. Show the predicted genotype and phenotype ratios! What is the genotype of the male? __________ What is the genotype of the female? ________ Genotype ratio 3. Let: B = Black coat color Phenotype ratio b= white coat color On a Punnett square, show the predicted results of a cross between a white male guinea pig and a heterozygous black female guinea pig. Show the predicted genotype and phenotype ratios! What is the genotype of the male? ________ Genotype ratio What is the genotype of the female? ________ Phenotype ratio 4. Let: L = Long wings l = short wings On a Punnett square, show the predicted results of a cross between two flies that are heterozygous for long wings. Show the predicted genotype and phenotype ratios! What is the genotype of the male? _________ What is the genotype of the female? ________ Genotype ratio 5. Let: W = White wool Phenotype ratio w = black wool In sheep, white wool is due to a dominant gene (W) and black wool is due to a recessive gene (w). A white ewe (♀) is mated with a white ram (♂) and their first offspring is a black lamb. a. What is the genotype of the male ram? __________ b. What is the genotype of the female ewe? __________ c. What is the genotype of the black lamb? __________ On a Punnett square, show that a mating between the white ewe and the white ram can produce a black lamb. Circle the black offspring on the Punnett square. Genotype ratio Phenotype ratio d. Is it possible for these two parents to produce a white lamb in the future? ________ e. If yes, would the offspring be homozygous white or heterozygous white? __________ f. What is the chance that the next offspring will be black? __________ White? ___________ Name: _________________________ 1. Let: E = Free ear lobes e = attached ear lobes Tad Jones has attached ear lobes. Tad Jones’ father has free ear lobes. Tad Jones’s mother has free ear lobes. Sarah Smith has free ear lobes. Sarah Smith’s father has free ear lobes. Sarah Smith’s mother has attached lobes. Tad Jones marries Sarah Smith and they have one child with attached ear lobes. Part A: What is the genotype of Tad Jones? ___________ What is the genotype of Tad’s father? __________ Tad’s mother? ____________ On a Punnett square, prove that Tad Jones’s father and mother could produce a child with attached ear lobes. Circle the genotype of Tad Jones on the Punnett square. Genotype ratio Phenotype ratio Part B: What is the genotype of Sarah Smith? _________________ What are the possible genotypes of Sarah’s father? _________ or __________ What is the genotype of Sarah’s mother? _____________ On a Punnett square, prove that Sarah Smith’s father and mother could produce a child with free ear lobes. Show both possibilities for Sarah Smith’s father! Circle the genotype of Sarah Smith on both Punnett squares. Be sure to show the genotype & phenotype ratios for each cross. Genotype ratio Genotype ratio Phenotype ratios Phenotype ratio Part C: What is the genotype of Tad and Sarah’s child? _____________ What is the genotype of Tad Jones? ___________ of Sarah Smith Jones? ____________ On a Punnett square, prove that Tad and Sarah could produce a child with the attached ear lobes trait. Circle Baby Jones on the Punnett square. Is it possible for Tad and Sarah to have children with free ear lobes? ____________ What is the chance their next child will have free ear lobes? __________ What is the chance their next child will have attached ear lobes? ________ Genotype ratio Phenotype ratio 2. Let: B = Black coat color b = white coat color A farmer has a black bull of undetermined genotype. The bull could be homozygous black or heterozygous black. To determine the genotype of the bull, the farmer could mate the black bull with a white cow. Why would crossing a black bull with a white cow help the farmer determine the genotype of the bull? ________________________________________________________________________________________ ________________________________________________________________________________________ Using the Punnett squares below, show the predicted results of a cross between a black bull that is heterozygous and a white cow and a bull that is homozygous black with a white cow. Show the predicted genotype and phenotype ratios for each. Genotype ratio Phenotype ratio Genotype ratio Phenotype ratio 3. In humans, straight toes (S) are dominant over curled toes (s). What would be the result of a cross between a recessive male and a heterozygous female? Set up a Punnett Square showing the results of this cross. Be sure to include genotype and phenotype ratios. 4. In dogs, erect ears (E) are dominant over droopy ears (e). What are the results if two heterozygous dogs have a litter of puppies? Set up a Punnett Square showing the results of this cross. Be sure to include genotype and phenotype ratios.
