Genetics and Hemoglobin Quiz
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the expected frequency of the aabb genotype if two AaBb individuals are crossed?

  • 1/2
  • 1/16 (correct)
  • 1/4
  • 1/8

    • Which of the following statements is TRUE regarding linked loci?

  • Recombination frequency is independent of the distance between linked loci.
  • Linked loci are always located on different chromosomes.
  • Linked loci are always inherited together. (correct)
  • The closer two linked loci are, the higher the recombination frequency between them.

    • What is the unit of measurement for genetic distance between two loci?

  • Micrometers (µm)
  • Centimorgans (cM) (correct)
  • Kilobases (kb)
  • Base pairs (bp)

    • What is the primary function of hemoglobin in red blood cells?

    <p>To transport oxygen from the lungs to the tissues. (A)</p> Signup and view all the answers

    Which of the following components is NOT a part of a single hemoglobin molecule?

    <p>cytoplasm (D)</p> Signup and view all the answers

    Where does oxygen bind to the hemoglobin molecule?

    <p>To the iron (Fe) ion in the heme unit (A)</p> Signup and view all the answers

    How many hemoglobin units are typically found in a single red blood cell?

    <p>270,000,000 (D)</p> Signup and view all the answers

    What does the term 'phenotype' refer to in the context of genetics?

    <p>The observable characteristics of an organism (D)</p> Signup and view all the answers

    According to the information provided, how many genes are associated with a single phenotype?

    <p>20 (A)</p> Signup and view all the answers

    What is the significance of the number 3,419 mentioned in the text?

    <p>The number of phenotypes associated with a single gene (D)</p> Signup and view all the answers

    Which of the following is NOT a way that mutations can affect protein function and cause disease?

    <p>Increased gene expression (B)</p> Signup and view all the answers

    What is meant by the term 'ectopic expression' in the context of protein function?

    <p>The production of a protein in the wrong location (D)</p> Signup and view all the answers

    What is the primary goal of the Online Mendelian Inheritance in Man (OMIM) database?

    <p>To provide comprehensive information about human genes and genetic disorders (D)</p> Signup and view all the answers

    What does "allelic editing" refer to in the context of the provided text?

    <p>Editing of specific variations within a gene (A)</p> Signup and view all the answers

    Which of the following is NOT a potential benefit of gene editing in the context of the provided text?

    <p>Complete eradication of the underlying genetic condition (D)</p> Signup and view all the answers

    Which of the following statements is TRUE regarding the relationship between genes and phenotypes?

    <p>Many phenotypes can be caused by a single gene (B), Many genes can contribute to a single phenotype (D)</p> Signup and view all the answers

    What is the significance of the large number of phenotypes (over 7,000) mentioned in the text?

    <p>It highlights the diversity of observable human traits (C)</p> Signup and view all the answers

    What does "SCD" stand for in the provided text?

    <p>Sickle Cell Disease (D)</p> Signup and view all the answers

    Why are mutations considered to be a significant factor in the development of diseases?

    <p>Mutations can alter protein structure and function (D)</p> Signup and view all the answers

    What is the significance of the numbers '7,480' and '4,878' mentioned in the text?

    <p>These numbers represent the total number of genes and phenotypes known to be affected by genetic disorders as of 2024 (A)</p> Signup and view all the answers

    Which of the following is NOT considered a type of misexpression?

    <p>Gain-of-function (C), Loss-of-function (D)</p> Signup and view all the answers

    What is the potential significance of "Check for 2025" mentioned in the text?

    <p>It suggests that the numbers of genes and phenotypes associated with genetic disorders are expected to increase by 2025 (D)</p> Signup and view all the answers

    Which of the following is NOT a potential application of CRISPR-Cas9 gene editing, based on the text provided?

    <p>Development of new therapies for infectious diseases (D)</p> Signup and view all the answers

    Which of the following is an example of a novel property mutation?

    <p>A single amino acid substitution in the beta-globin gene causing Hb Kempsey (C)</p> Signup and view all the answers

    What is the relationship between "genotype" and "phenotype" in the context of the provided information?

    <p>Genotype refers to the genetic makeup of an individual, while phenotype refers to the physical traits and characteristics of an individual (B)</p> Signup and view all the answers

    Which of the following is NOT an example of a gain-of-function mutation?

    <p>A deletion in the <em>RB1</em> gene causing retinoblastoma (D)</p> Signup and view all the answers

    Based on the provided text, what is the primary target of CRISPR-Cas9 gene editing in the context of sickle cell disease and β-thalassemia?

    <p>The genes responsible for the production of hemoglobin (A)</p> Signup and view all the answers

    What does "OMIM" stand for in the text?

    <p>Online Mendelian Inheritance of Man (B)</p> Signup and view all the answers

    What is a common characteristic of gain-of-function mutations?

    <p>They can enhance a normal function of a protein. (B)</p> Signup and view all the answers

    What is the primary mechanism by which tumor suppressor genes like TP53 and RB1 prevent cancer development?

    <p>By regulating cell cycle checkpoints and preventing uncontrolled cell proliferation. (D)</p> Signup and view all the answers

    Which of the following is a key characteristic of a tumor suppressor gene mutation?

    <p>They usually result in a loss-of-function mutation. (A)</p> Signup and view all the answers

    What is the name of the gene responsible for encoding the β subunit of hemoglobin?

    <p>HBB (C)</p> Signup and view all the answers

    Which amino acid is substituted for Glutamic acid at position 6 in the β subunit of hemoglobin in sickle cell disease?

    <p>Valine (B)</p> Signup and view all the answers

    What is the primary effect of the Glu6Val mutation in the β-globin subunit on deoxygenated hemoglobin?

    <p>Decreased solubility (C)</p> Signup and view all the answers

    What is the role of the spleen in sickle cell disease?

    <p>Removal of irreversibly sickled cells (D)</p> Signup and view all the answers

    What is the primary mechanism by which sickled erythrocytes cause tissue damage?

    <p>Blockage of capillaries (A)</p> Signup and view all the answers

    What is the role of gamma (γ) subunits in fetal hemoglobin?

    <p>They replace the β subunit in adult hemoglobin (B)</p> Signup and view all the answers

    What is the significance of understanding sickle cell disease at the molecular level?

    <p>It allows for the development of treatments that target specific genes (B)</p> Signup and view all the answers

    What is the role of CRISPR-Cas9 in treating sickle cell disease?

    <p>It targets the BCL11A enhancer to activate fetal hemoglobin production (C)</p> Signup and view all the answers

    What is the significance of using autologous CD34+ cells in CRISPR-Cas9 therapy for sickle cell disease?

    <p>They are responsible for producing red blood cells (C)</p> Signup and view all the answers

    Flashcards

    Dominant Alleles

    Alleles that express their trait even when paired with a recessive allele.

    Recessive Alleles

    Alleles that only express their trait when paired with another recessive allele.

    Independent Assortment

    Mendel's principle stating alleles for different traits assort independently of one another.

    Linked Loci

    Genes located close together on the same chromosome that tend to be inherited together.

    Signup and view all the flashcards

    Centimorgans

    Unit of measure for genetic linkage, representing the distance between loci. 1 cM = 1% recombination frequency.

    Signup and view all the flashcards

    Red Blood Cells (RBCs)

    Cells that carry oxygen throughout the body, shaped like biconcave discs.

    Signup and view all the flashcards

    Hemoglobin Structure

    Protein in RBCs consisting of four heme units, two alpha units, and two beta units.

    Signup and view all the flashcards

    Phenotypes

    Observable characteristics of an organism resulting from gene expression.

    Signup and view all the flashcards

    Gain-of-Function Mutations

    Mutations that enhance or increase the function of a protein, potentially causing disorders.

    Signup and view all the flashcards

    Retinoblastoma

    A type of cancer caused by deletions in the RB1 tumor-suppressor gene.

    Signup and view all the flashcards

    Charcot-Marie-Tooth Disease

    A neurological disorder from PMP22 gene duplication, leading to muscle loss and gait issues.

    Signup and view all the flashcards

    Novel Property Mutations

    Changes in amino acids that add new properties to a protein without altering its original function.

    Signup and view all the flashcards

    Sickle Cell Disease

    An autosomal recessive disorder characterized by a mutation in β-globin.

    Signup and view all the flashcards

    Autosomal Recessive Disorder

    A disease that requires two copies of the mutated gene to manifest.

    Signup and view all the flashcards

    HBA and HBB Genes

    Genes encoding α and β subunits of hemoglobin respectively.

    Signup and view all the flashcards

    Glu6Val Mutation

    Missense mutation substituting Valine for Glutamic acid at amino acid 6.

    Signup and view all the flashcards

    Deoxygenated Hemoglobin

    Less soluble form of hemoglobin that sickles under low oxygen.

    Signup and view all the flashcards

    Hemolytic Anemia

    Condition caused by the destruction of sickled erythrocytes by the spleen.

    Signup and view all the flashcards

    Capillary Occlusion

    When sickled erythrocytes block blood flow, causing tissue death.

    Signup and view all the flashcards

    CRISPR-Cas9

    A gene-editing technology used to target specific genetic alterations.

    Signup and view all the flashcards

    BCL11A Enhancer

    A genetic element targeted by CRISPR to potentially treat sickle cell.

    Signup and view all the flashcards

    Genes

    Units of heredity made up of DNA that influence an organism's traits.

    Signup and view all the flashcards

    Loss-of-function mutation

    A mutation that decreases or eliminates the normal function of a protein.

    Signup and view all the flashcards

    Acquisition of a novel property

    A mutation that gives a protein a new or unique function not present in the wild-type protein.

    Signup and view all the flashcards

    Misexpression

    The inappropriate expression of a gene or protein at the wrong time or in the wrong context.

    Signup and view all the flashcards

    Ectopic expression

    Expression of a protein in an incorrect location within an organism.

    Signup and view all the flashcards

    Heterochronic expression

    Expression of a gene at an atypical time during development.

    Signup and view all the flashcards

    OMIM

    Online Mendelian Inheritance in Man, a catalog of human genes and genetic disorders.

    Signup and view all the flashcards

    Number of genes associated with a single phenotype

    The number of distinct genes that can influence one observable trait.

    Signup and view all the flashcards

    Allelic Editing

    The process of changing specific alleles in DNA.

    Signup and view all the flashcards

    Transfusion Independence

    A patient's ability to maintain normal blood levels without transfusions.

    Signup and view all the flashcards

    Vaso-Occlusive Episodes

    Pain crises due to blockages in blood vessels, common in sickle cell disease.

    Signup and view all the flashcards

    Sickle Cell Disease (SCD)

    A genetic blood disorder causing sickle-shaped red blood cells.

    Signup and view all the flashcards

    Transfusion-Dependent β-Thalassemia (TDT)

    A blood disorder requiring regular blood transfusions to survive.

    Signup and view all the flashcards

    Genotype

    The genetic makeup of an organism; specific alleles present.

    Signup and view all the flashcards

    Gene Map Statistics

    Data on the number of identified genes and phenotypes available.

    Signup and view all the flashcards

    Study Notes

    Molecular, Biochemical, and Cellular Basis of Genomic Disease

    • The lecture covers the molecular, biochemical, and cellular underpinnings of genomic diseases.

    Objectives of This Lecture

    • Illustrate the fundamental mechanism behind genetic variation.
    • Explain different types of mutations.
    • Describe the effect of mutations on protein function.
    • Describe protein classification based on expression patterns and tissue specificity.
    • Understand genetic and phenotypic heterogeneity.
    • Describe the relationships between protein expression sites and diseases.
    • Describe diseases discussed in the lecture.

    Genetic Variation Among Humans

    • Substantial variations exist among humans (e.g., skin color, height, hair color, susceptibility).
    • Mutation: any change in DNA sequence.
    • Mutations in humans often cause genetic disease, typically affecting single genes and not microscopically apparent.
    • Mutations can occur in coding or regulatory DNA sequences.
    • Germline cells transmit mutations to the next generation, somatic cells do not.
    • Allele: alternative forms/versions of a gene.
    • Locus: a gene's location on a chromosome.
    • Polymorphism: existence of multiple alleles for a gene in a population.

    Molecular Basis of a Disease

    • Molecular disease: disease traced back to a single molecular factor (e.g., protein, polypeptide).
    • Mutation (inherited or acquired) is the primary cause of molecular disease
    • Understanding molecular pathology is critical for treating genetic diseases and understanding normal functions.
    • Biochemical genetics studies relationships between genes and observable traits (phenotypes) at the protein production, function, biochemistry, and metabolism (e.g., turnover) levels.

    Types of Mutations

    • Base-pair substitutions (point mutations): Single base changes.
    • Base-pair deletions or insertions: Removal or addition of base pairs in DNA.
    • Splice-site mutations: Affect the splicing process.
    • Gene duplications/deletions: Changes in gene number.
    • Promoter mutations: Affect gene expression.
    • Mobile element insertion: Movement of DNA segments.
    • Expanded repeats: Repetition of DNA sequences.

    Dominant Alleles and Recessive Alleles

    • Alleles determine traits.
    • Dominant alleles express their trait even with one copy.
    • Recessive alleles only express their trait with two copies.

    Dominant Alleles and Recessive Alleles

    • A depiction of how offspring inherit traits based on dominant and recessive alleles is illustrated
    • Relationships between the genotype and phenotype are explained with diagrams

    Linked Loci

    • Loci on the same chromosome tend to be inherited together
    • Physical distance between linked loci influences the frequency of recombination.
    • Recombination frequency is used to map the relative locations of genes on chromosomes.

    Red Blood Cells: Structure and Function

    • Red blood cells (erythrocytes) are biconcave discs without a nucleus.
    • They contain hemoglobin.
    • Each red blood cell contains millions of hemoglobin units.
    • Hemoglobin consists of 2 alpha and 2 beta units.
    • Each heme unit contains iron for oxygen bonding.

    Sickle Cell Disease

    • a subunit encoded by HBA on chromosome 16.
    • ẞ subunit encoded by HBB gene on chromosome 11.
    • Sickle cell disease is an autosomal recessive disorder of hemoglobin.
    • A missense mutation substitutes valine for glutamic acid at amino acid 6 of the β-globin gene.
    • This mutation reduces the solubility of deoxygenated hemoglobin, causing the cells to sickle.

    Importance of understanding disease at molecular level

    • The transition from fetal to adult hemoglobin illustrates the importance of understanding disease at the molecular level.
    • Genetic editing using CRISPR-Cas9 can target disease-causing mutations to cure the disease.

    Genotype vs Phenotype

    • A link exists between the genotype and phenotype.
    • Large numbers of genes and phenotypes are linked.
    • Over 7000 phenotypes and nearly 4000 genes are associated.

    Effect of Mutation on Protein Function

    • Mutations can affect protein function in 4 ways:
    • Loss-of-function.
    • Gain-of-function.
    • Novel properties.
    • Misexpression.

    Loss-of-Function Mutations

    • Alterations in a gene's sequence can lead to loss-of-function.
    • Examples include nonsense mutations, missense mutations impacting protein stability, and decreased protein abundance.
    • Disease severity often correlates with the degree of lost function.

    Loss of Protein Function Mutations (Thalassemia)

    • Thalassemia results from reduced or absent globin production.
    • Alpha thalassemia involves deficiencies in alpha globin chains, resulting in excess beta chains.
    • Beta thalassemia involves deficiencies in beta globin chains, resulting in excess alpha chains.
    • Both forms lead to premature erythrocyte destruction and anemia.

    Gain-of-Function Mutations

    • Mutations can enhance normal functions of a protein or create novel ones.
    • Examples include increased protein production or altered protein activity.

    Novel Property Mutations (e.g., Sickle Cell Disease)

    • Changes in amino acid residues can generate novel protein properties without altering normal functions.
    • This involves mutations altering the biochemical properties of the protein, and creating new qualities that cause disease.

    Mutations Associated with Heterochronic or Ectopic Gene Expression

    • Mutations in regulatory regions cause abnormal gene expression inappropriate times or locations.
    • This can lead to diseases like malignancy, or hereditary persistence of fetal hemoglobin due to mutations in the regulatory elements.

    Ways for Mutations to Disrupt the Synthesis or Function of a Normal Protein

    • Mutations can disrupt protein production and function at various steps, such as transcription, translation, folding, post-translational modification, assembly, subcellular localization, and cofactor binding.

    Classification of Proteins

    • Proteins are classified based on expression patterns;
    • Housekeeping proteins: expressed in all cells; fundamental.
    • Tissue-specific proteins: expressed in specific cells; unique functions.

    Relationship Between Site of Protein Expression and Disease

    • Mutations in tissue-specific proteins can cause diseases restricted to those tissues.
    • Disease can also occur in other tissues, that do not express the defective protein.

    Relationship Between Site of Protein Expression and Disease (Cont'd)

    • Mutations in housekeeping proteins rarely cause severe, widespread diseases.
    • Genetic redundancy or protein abundance can mitigate the impact of mutations in certain cases.

    Genetic Heterogeneity vs. Pleiotropy

    • Genetic heterogeneity: Different mutations can lead to the same phenotype.
    • Pleiotropy: A single gene mutation can cause multiple phenotypes.

    Protein Abnormalities and Genetic Diseases

    • Mutations in functional classes of proteins lead to genetic disorders.
    • These mutations affect various cellular components affecting their function.

    How to classify mutations that disrupt cell and organ functions

    • A classification system for mutations is needed, that describes and explains how different types of mutations can disrupt cell and organ function.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    The Molecular, Biochemical, and Cellular Basis of Genomic Disease PDF

    Description

    Test your knowledge on genetics and hemoglobin functions with this quiz. It covers topics including genotype frequency, linked loci, and the role of hemoglobin in red blood cells. Perfect for genetics enthusiasts or students studying the subject.

    More Like This

    Lec 3 - MCQ Genetics Quiz
    70 questions

    Lec 3 - MCQ Genetics Quiz

    PrudentRainforest avatar
    PrudentRainforest
    Sickle Cell Disease Pathophysiology
    8 questions

    Sickle Cell Disease Pathophysiology

    FeistyEuropium avatar
    FeistyEuropium
    Sickle Cell Disease: Definition and Causes
    8 questions

    Sickle Cell Disease: Definition and Causes

    FeistyEuropium avatar
    FeistyEuropium
    Sickle Cell Anemia Overview
    5 questions

    Sickle Cell Anemia Overview

    ThankfulRetinalite365 avatar
    ThankfulRetinalite365
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser