Human Heredity: Principles and Issues (MindTap Course List)
11th Edition
ISBN: 9781305251052
Author: Michael Cummings
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 11, Problem 20QP
The cystic fibrosis gene encodes a chloride channel protein necessary for normal cellular functions. Let us assume that if at least 5% normal channels are present, the affected individual has mild symptoms of cystic fibrosis. Having less than 5% normal channels produces severe symptoms. At least 50% of the channels must be expressed for the individual to be
Predict the percent of functional channels and severity of symptoms for the following genotypes:
- a. heterozygous for CF100
- b. homozygous for CF100
- c. heterozygous, with one copy of CF100 and one of CF3
- d. heterozygous, with one copy of CF1 and one copy of CF3
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
Hurler syndrome is due to a mutation in a gene that encodes aprotein called α-l-iduronidase. This protein functions withinlysosomes as an enzyme that breaks down mucopolysaccharides(a type of polysaccharide that has many acidic groups attached).When this enzyme is defective, excessive amounts of the mucopolysaccharides dermatan sulfate and heparin sulfate accumulatewithin the lysosomes, especially in liver cells and connectivetissue cells. This accumulation leads to symptoms such as anenlarged liver and spleen, bone abnormalities, corneal clouding,heart problems, and severe neurological problems. The pedigreebelow contains three members affected with Hurler syndrome,indicated with black symbols. Based on this pedigree, does thissyndrome appear to follow autosomal recessive, autosomaldominant, X-linked recessive, or X-linked dominant inheritance?Explain your reasoning.
Troponin is a complex composed of Troponin C (TnC), Troponin I (TnI), and Troponin T (TnT); the complex is found in skeletal and cardiac muscle, but not smooth muscle. Two "isoforms" of TnI and two "isoforms" of TnT are expressed in human skeletal muscle tissue.
Q:The isoforms of TnI in the sentence above mean:
A:One single TnI gene encodes two different TnI proteins as a result of alternative splicing of the TnI pre-mRNA.
B:There are two different TnI genes, each produces a TnI protein.
In humans, the disease cystic fibrosis is caused by a recessive allele for a gene that encodes a specific type of channel protein. Using C as a “normal” allele for the disease, under what conditions is it possible for a child with cystic fibrosis to have biological parents who do not have the disease?
Both parents have the genotype Cc
It is not possible for this to occur
Both parents have the genotype CC
Chapter 11 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
Ch. 11.4 - Consumer products including bandages, cotton...Ch. 11.4 - Prob. 2EGCh. 11 - Prob. 1CSCh. 11 - Prob. 2CSCh. 11 - Prob. 3CSCh. 11 - Prob. 1QPCh. 11 - Achondroplasia is an autosomal dominant form of...Ch. 11 - Why is it almost impossible to directly measure...Ch. 11 - What are the factors that influence the mutation...Ch. 11 - Achondroplasia is a rare dominant autosomal defect...
Ch. 11 - Although it is well known that X-rays cause...Ch. 11 - Prob. 7QPCh. 11 - Bruce Ames and his colleagues have pointed out...Ch. 11 - Define and compare the following types of...Ch. 11 - If the coding region of a gene (the exons)...Ch. 11 - Two types of mutations discussed in this chapter...Ch. 11 - Prob. 12QPCh. 11 - A frameshift mutation is caused by a: a....Ch. 11 - In the gene-coding sequence shown here, which of...Ch. 11 - Prob. 15QPCh. 11 - Familial retinoblastoma, a rare autosomal dominant...Ch. 11 - Tay-Sachs disease is an autosomal recessive...Ch. 11 - Replication involves a period of time during which...Ch. 11 - Our bodies are not defenseless against mutagens...Ch. 11 - The cystic fibrosis gene encodes a chloride...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Cystic fibrosis is a disease that occurs when an individual carries two copies of a recessive version of a membrane transport gene. A person that is a carrier for cystic fibrosis (that means they carry one copy of the gene that causes cystic fibrosis but their other copy is normal - they do not have cystic fibrosis) has a child with another person that is also a carrier for cystic fibrosis. What is the probability that this couple has three children that do not have cystic fibrosis AND are also not carriers of cystic fibrosis? 0.25 0.422 0.016 2.25 0.75arrow_forwardSerotonin is a neurotransmitter that is a small, soluble molecule. P11 (a small protein) is required for transport of serotonin receptors to the cell surface. Assume for this problem that p11 affects transport of serotonin receptors only, and that it does not affect transport of any other proteins (a simplification). Depressed people seem to have low levels of p11; treatments that improve mood increase the expression of the p11 gene. NSAIDs (aspirin, ibuprofen, etc.) seem to decrease expression of p11. SSRIs (selective serotonin reuptake inhibitors) decrease re-uptake of serotonin at synapses. Some depressed patients are helped by SSRIs, but some are not. Explain both parts of B. B-1. The results indicate that depression can be caused by levels of serotonin receptors that are (higher than normal) (lower than normal) (neither – no evidence here for any effect on depression) (higher or lower but can't tell which). B-2. If a depressed person does not respond to SSRIs, the person…arrow_forwardA human gene called theCFTR gene (for cystic fibrosis transmembrane regulator) encodes aprotein that functions in the transport of chloride ions across the cellmembrane. Most people have two copies of a functional CFTR geneand do not have cystic fibrosis. However, a mutant version of the CFTRgene is found in some people. If a person has two mutant copies ofthe gene, he or she develops the disease known as cystic fibrosis. Arethe following descriptions of this disease related to genetics at themolecular, cellular, organism, or population level?A. People with cystic fibrosis have lung problems due to a buildupof thick mucus in their lungs.B. The mutant CFTR gene encodes a defective chloride transporter.C. A defect in the chloride transporter causes a salt imbalance inlung cells.D. Scientists have wondered why the mutant CFTR gene is relativelycommon. In fact, it is the most common mutant gene that causesa severe disease in persons of Northern European descent. Onepossible explanation why…arrow_forward
- Cystic fibrosis (CF) is a genetic disorder caused by mutations in the CFTR (cystic fibrosis transmembrane-conductance regulator) gene, which encodes the CFTR protein. The cells of the lining of the lungs contain high levels of the CFTR protein in their membranes. Normally, CFTR contains a chloride ion channel, which permits chloride ions to pass from inside the cells to the cells’ surfaces. The surface chloride ions are able to attract water in the lungs, allowing for the formation of a water layer on the cells’ surfaces. This thin water layer is necessary to allow the cilia, the tiny hairs on the surface of the lining cells to move back and forth easily. This motion permits the removal of mucus from the lungs. A particular error in the CFTR gene results in the replacement of the amino acid Phe with Ser at residue 508 of the CFTR protein. Individuals afflicted with CF most often experience the presence of thick, dry and sticky mucus in the lungs, leading to chronic infections and…arrow_forwardIndividuals with the hereditary disorder ataxia telangiectasia suffer from neurodegeneration, immunodeficiency, and an increased incidence of cancer. The genetic basis for ataxia telangiectasia is a loss-of-function mutation in the gene encoding ATM (ATM; ataxia telangiectasia mutated). Besides p53, what other substrate is phosphorylated by ATM? How does the phosphorylation of this substrate lead to inactivation of CDKs to enforce cell cycle arrest?arrow_forwardProteins found in the blood respond to blood vessel damage by clumping together forming a clot that physically blocks the hole in the vessel and prevents further blood loss. If clotting proteins were active all the time, they would create clots throughout your circulatory system. Which of the following would be the most efficient way for the body to regulate the expression of the proteins involved in clotting? A. Tightly package the genes for clotting proteins so that RNA polymerase cannot access them unless they are needed. B. Produce and store the clotting protein in an inactive form. When the protein is needed, use another protein to activate the clotting protein. C. Constantly make the clotting proteins, but then break them down instantly after translation if they are not needed. D. Use a repressor protein to keep clotting genes turned off until they are needed.arrow_forward
- During periods of sustained demand and in the presence of sufficient nutrients, muscle cells can increase in size. When the size of muscle cells increases, they will often develop additional nuclei in their intracellular environment. Which of the following is the most likely explanation for the expression of additional nu- clei in growing muscle cells? A B с D Nutrients entering the cells will be digested and recycled more quickly by the additional nuclei to better support the subcellular components in the cell as its size increases. The ATP molecules that are produced in the additional nuclei will be able to better sup- port the increased energetic demands on the muscle cell as its size increases. The addition of more nuclei to the cell will allow more genetic information to be stored in the cell and allow the cell to produce additional types of proteins as its size increases. Additional nuclei allow subcellular components to continue to be sufficiently expressed and transferred…arrow_forwardLike Hurler syndrome, Fabry disease involves an abnormal accumulationof substances within lysosomes. However, the lysosomes of individuals with Fabry disease show an abnormal accumulation of lipids. The defective enzyme is α-galactosidase A, which is a lysosomal enzyme that functions in lipid metabolism. The defect causes cell damage, especially to the kidneys, heart, and eyes. The gene that encodes α-galactosidase A is found on the X chromosome. Let’s suppose a phenotypically unaffected couple producestwo sons with Fabry disease and one phenotypically unaffecteddaughter. What is the probability that the daughter will have anaffected son?arrow_forwardLike Hurler syndrome, Fabry disease involves an abnormal accumulationof substances within lysosomes. However, the lysosomesof individuals with Fabry disease show an abnormal accumulationof lipids. The defective enzyme is α-galactosidase A, which is alysosomal enzyme that functions in lipid metabolism. The enzymaticdefect causes cell damage, especially to the kidneys, heart,and eyes. The gene that encodes α-galactosidase A is found on theX chromosome. Let’s suppose a phenotypically unaffected coupleproduces two sons with Fabry disease and one phenotypicallyunaffected daughter. What is the probability that the daughter willhave an affected son?arrow_forward
- Marfan syndrome is due to a mutation in a gene that encodes aprotein called fibrillin-1. It is inherited as a dominant trait. Thefibrillin-1 protein is the main constituent of extracellular microfibrils.These microfibrils can exist as individual fibers or associatewith a protein called elastin to form elastic fibers. People with thedisorder tend to be unusually tall with long limbs, and they mayhave defects in their heart valves and aorta. Let’s suppose aphenotypically unaffected woman has a child with a man whohas Marfan syndrome.A. What is the probability this child will have the disease?B. If this couple has three children, what is the probability thatnone of them will have Marfan syndrome?arrow_forwardIn an experimental motile fibroblast cell line, Nucleation Promoting Factor (NPF) was mutated in such a way that it no longer could bind to the G-actin monomers. Which of the following would you observe in these cells as a consequence of the mutation at the molecular level? None of the other is true. The cell will not be able to form branching of the actins using Arp2/3 complex at the leading edge and causing movement arrest The filamin protein will not be recruited for crosslinking the actins and will cause the arrest of movement. The Arp2/3 and filamin will not be able to dissociate from actin in the absence of NPF and the cells will be restricted to move in one direction onlyarrow_forwardWhich of the following is true when considering the calcineuron-NFAT pathway? Choose all that are true. Calcineuron removes Pi from NFATC in the presence of Ca2+. Trisomy 21 alters the dosage of DYRK1A and calcineuron. The addition of Pi to NFATc results in an increase in gene expression. The removal of Pi from NFATC is inhibited by DSCR1.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
TISSUE REPAIR Part 1: Repair - Regeneration; Author: ilovepathology;https://www.youtube.com/watch?v=t-5EjlS6qjk;License: Standard YouTube License, CC-BY