Concept explainers
The following pedigree is for myopia (nearsightedness) in humans.
Predict whether the disorder is inherited as the result of a dominant or recessive trait. Determine the most probable genotype for each individual based on your prediction.
HINT: This problem asks you to analyze a pedigpee and determine the mode of inheritance of myopia. The to its solution is to identify whether or not there are individuals who express the trait but neither of whose parents also express the trait. Such an observation is a powerful clue and allows you to rule out one mode of inheritance.
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
Concepts of Genetics (12th Edition)
Additional Science Textbook Solutions
Human Anatomy & Physiology (Marieb, Human Anatomy & Physiology) Standalone Book
Microbiology with Diseases by Body System (4th Edition)
Brock Biology of Microorganisms (14th Edition)
Biology: Life on Earth
Genetic Analysis: An Integrated Approach (3rd Edition)
Brock Biology of Microorganisms (15th Edition)
- a) Which of the four modes of inheritance are consistent with the disease shown in this human pedigrees below? (List the compatible mode or modes) Give an answer for a, b and c b) If the parents in pedigree c have 2 other children, what is the probability that they will carry the disease?arrow_forwardWhich mode of inheritance is suggested by the following pedigree? Based on this hypothesis, and assuming that the trait is rare and has complete penetrance, what are the possible genotypes of all individuals in this pedigree?arrow_forwardMarfan syndrome is a disease caused by a rare dominant allele of the fibrillin-1 gene. Fibrillin-1 is an important component of the extracellular matrix, and people with the disease-causing allele have abnormal connective tissue. An affected mother (Marta) and an unaffected father (Joe) have one unaffected daughter (Luisa - she does not exhibit any traits of the syndrome). If Luisa has a child with Nico (unaffected), what is the probability that her child will inherit Marfan syndrome? Select one: a. 50% b. 25% c. 100% d. 0% e. 75%arrow_forward
- Using the pedigree chart attached: Above is a pedigree for colorblindness. Based on the pedigree, is the disease dominant or recessive and is it sex-linked or autosomal? Why? Furthermore, what is the probability that 18 on this chart is affected but the condition, and what is the probability that 18 is a carrier? Why? Are the probability of being a carrier and an affected individual different? Why?arrow_forwardBelow is a pedigree of a human genetic disease in which solid color indicates affected individuals. Assume that the disease is caused by a gene that can have the alleles A or a. a) Based on this pedigree, what is the most likely mode of inheritance? b) What is/are the possible genotype/s of person 1? c) What is/are the possible genotype (s) of person 4 ? Explain your answers.arrow_forwardEctrodactyly is a rare condition in which the fingers are absent and the hand is split. This condition is usually inherited as an autosomal dominant trait. Ademar Freire-Maia reported the appearance of ectrodactyly in a family in São Paulo, Brazil, whose pedigree is shown here. Is this pedigree consistent with autosomal dominant inheritance? If not, what mode of inheritance is most likely? Explain your reasoning.arrow_forward
- the lubber grasshopper is a very large grasshopper,and is black and red and yellow stripes.Assume that red strpes are expressed from Gr alleles,yellow stripes from the Gy allele,and no stripes from the g allele.What will be the phenotype ratio resulting from a cross of two grasshoppers,both with red and yellow stripes? what type of inheritance is occurring in this situation ?arrow_forwardRead the following family history and draw a pedigree to determine the inheritance pattern for achondroplasia. Once the pedigree is assembled , label the genotypes of each individual using a capital "A to represent the dominant allele and a lower case "a " to represent the recessive allele and create a key to identify which version is the achondroplasia allele. If you are unsure of the genotype , label the individual with a "" in place of the unknown allele. Family History : Jada and Noel , both of short stature, have been married for twenty years. They have three children : an eighteen - year-old boy named Shawn , of short stature ; a fifteen- year- old boy named John , of short stature ; and a twelve -year -old girl named Ann , of average height Noel and Jada also had a male child bom with severe achondroplasia who died six months after birth from respiratory failure . Noel's father was of short stature , while his mother was average height . Noel has a brother and a…arrow_forward—Hereditary canine spinal muscular atrophy (HCSMA) is a motor neuron disease in Brittany Spaniels. Breeding studuies within a kindred of more than 125 dogs (Brittany spaniel and beagle-Brittany outcrosses) have established an autosomal dominant inheritance for HCSMA. Which of the following genotypes would cause the dog to NOT HAVE HCSMA? Hh HH Hh A and C B and C– —(see question above for genotype) is a spaniel who is homozygous recessive for the HCSMA trait had a puppy with a spaniel who was heterozygous for this trait, what is the probability that the puppy would be normal? 0% 25% 50% 75% 100%arrow_forward
- The following pedigree illustrates the inheritance of ringed hair, a condition in which each hair is differentiated into light and dark zones. What mode or modes of inheritance are possible for the ringed-hair trait in this family?arrow_forwardIn a testcross, the parent that is homozygous recessive for the genes being studied is called the testcross parent. The parent that has the dominant phenotype of the genes being studied is called the non-testcross parent.Which of the following is NOT a reason that a testcross is a useful technique when studying the inheritance of a trait? a. A testcross can determine if an individual with the dominant phenotype is homozygous or heterozygous. b. The relative frequencies of the different phenotypes among the testcross progeny can be used to map linked genes. c. Because the testcross parent can contribute only recessive alleles, the alleles contributed by the other parent will be expressed in the offspring of the testcross. d. The gametes produced by the testcross parent are determined from the testcross progeny.arrow_forwardSkin color is one of the traits in a human which is determined by polygenic inheritance system because it is possibly involving as many as 9 genes. To make this simple, let us consider the influence of 2 genes: A and B., where dark skin color is dominant. Suppose a man who is AABb marries a woman who is Aabb, what would be the genotypes of their children. Prove your answer by using a Punnet Square.arrow_forward
- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage LearningHuman Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning