Genetics: Autosomal Recessive Disorders
41 Questions
1 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 must be true for a person to have an autosomal recessive disorder?

  • The disorder affects males only.
  • The disorder is inherited from the father only.
  • Both copies of the recessive allele must be present. (correct)
  • Only one copy of the recessive allele is needed.

    • Males can be carriers for sex-linked diseases.

    False

    What genetic notation represents a healthy individual in autosomal recessive disorders?

    C

    Cystic fibrosis is an example of an autosomal ______ disorder.

    <p>recessive</p> Signup and view all the answers

    Which of the following statements about sex chromosomes is correct?

    <p>Y chromosome genes are responsible for male characteristics.</p> Signup and view all the answers

    Match the following genetic disorders with their inheritance type:

    <p>Cystic fibrosis = Autosomal recessive Huntington's disease = Autosomal dominant Color blindness = Sex-linked Sickle cell disease = Autosomal recessive</p> Signup and view all the answers

    In males, sex-linked traits are expressed due to the lack of a second ______ chromosome.

    <p>X</p> Signup and view all the answers

    What characteristic is true of autosomal dominant disorders?

    <p>Both males and females are equally likely to be affected.</p> Signup and view all the answers

    In autosomal recessive traits, affected parents will always have affected offspring.

    <p>True</p> Signup and view all the answers

    What is the genotype for a person with a widow's peak?

    <p>Ww or WW</p> Signup and view all the answers

    If both parents are carriers of an autosomal recessive trait, the probability of having an affected child is _____%.

    <p>25</p> Signup and view all the answers

    Match the type of inheritance with its characteristic:

    <p>Autosomal Dominant = Affected offspring in every generation Autosomal Recessive = Normal parents may have affected children Sex-Linked = Typically transmitted through X chromosome Autosomal = Both genders can inherit the trait equally</p> Signup and view all the answers

    Which of the following traits is X-linked recessive?

    <p>Color blindness</p> Signup and view all the answers

    Female mammals express both copies of sex-linked genes due to random X chromosome inactivation.

    <p>False</p> Signup and view all the answers

    What is codominance?

    <p>Both alleles of a gene are expressed completely.</p> Signup and view all the answers

    The _____ gene can overshadow the expression of other genes for a specific trait.

    <p>epistatic</p> Signup and view all the answers

    Match the sex-linked traits to their type:

    <p>Haemophilia = X-linked recessive Rett Syndrome = X-linked dominant Albinism = Epistasis Color blindness = X-linked recessive</p> Signup and view all the answers

    What percentage of F1 offspring will have blood group O from a male with IA i and a female with IB i blood group?

    <p>25%</p> Signup and view all the answers

    Human eye color is considered a polygenic trait.

    <p>True</p> Signup and view all the answers

    Provide an example of a trait influenced by environmental factors.

    <p>Sex of turtles based on incubation temperature.</p> Signup and view all the answers

    Female turtles bury their eggs in the sand, and warmer temperatures lead to the development of _____ turtles.

    <p>female</p> Signup and view all the answers

    What is the expected percentage of females that are color blind in the F1 generation when a color blind male mates with a heterozygous normal female?

    <p>50%</p> Signup and view all the answers

    Males can be carriers for X-linked disorders.

    <p>False</p> Signup and view all the answers

    What are the genotypes of the predicted F1 offspring when a color blind male mates with a heterozygous normal female?

    <p>XcX, XcY, XX, XY</p> Signup and view all the answers

    Males have _____ chromosomes, which include one X and one Y.

    <p>XY</p> Signup and view all the answers

    Match the following genotypes with their corresponding phenotypes:

    <p>XcX = Heterozygous normal female XcY = Color blind male XX = Normal female XY = Normal male</p> Signup and view all the answers

    What is the probability of color blind males in the F1 generation?

    <p>50%</p> Signup and view all the answers

    Color blindness is a dominant disorder.

    <p>False</p> Signup and view all the answers

    What type of inheritance is demonstrated when a curly haired man and a straight haired woman produce 100% wavy haired offspring?

    <p>Incomplete dominance</p> Signup and view all the answers

    Describe what a pedigree is used for.

    <p>A pedigree is a chart used to trace phenotypes and genotypes in a family to determine if individuals carry recessive alleles.</p> Signup and view all the answers

    All males will be affected by hypertrichosis if a male with the condition marries a normal female.

    <p>True</p> Signup and view all the answers

    Females can be _____ of X-linked disorders due to their XX chromosome composition.

    <p>carriers</p> Signup and view all the answers

    What is the genotype of a normal male in the context of hemophilia?

    <p>XHY</p> Signup and view all the answers

    Which of the following statements is true regarding X-linked disorders?

    <p>Males are more likely to be affected than females.</p> Signup and view all the answers

    In Rett syndrome, the genotype for a heterozygous female is XHXh, where H represents __________.

    <p>affected</p> Signup and view all the answers

    Match the genetic disorders with their inheritance types:

    <p>Rett syndrome = X-linked dominant Hemophilia = X-linked recessive Hypertrichosis = Y-linked Hair texture inheritance = Incomplete dominance</p> Signup and view all the answers

    What will be the likely phenotype percentage of offspring from a heterozygous female and a normal male regarding hemophilia?

    <p>50% affected males, 0% affected females</p> Signup and view all the answers

    In the scenario involving a normal male and a heterozygous female with Rett syndrome, all offspring will be normal.

    <p>False</p> Signup and view all the answers

    What percentage of the F1 generation will be affected when a male with hypertrichosis marries a normal female?

    <p>0%</p> Signup and view all the answers

    In the Punnett square for hemophilia, the percentage of females that might be hemophilic is __________.

    <p>0%</p> Signup and view all the answers

    How does temperature affect the sex of turtle offspring?

    <p>Cooler temperatures result in male turtles.</p> Signup and view all the answers

    Study Notes

    Chromosomes and Phenotype

    • The chromosomes' location of genes affects trait expression.
    • Sex chromosomes determine sex (XX = female, XY = male).
    • Autosomes are the other chromosomes.
    • Two copies of each autosomal gene impact phenotype.
    • Mendel studied autosomal traits (e.g., hair texture).
    • Autosomal traits are carried on autosomes (22 pairs in humans).
    • Genotype is expressed by letters (e.g., eye color).

    Disorders Caused by Autosomes

    • Recessive alleles must be present for a disorder.
    • Someone with heterozygous alleles is a carrier.
    • Cystic fibrosis is an autosomal recessive disorder.

    Disorders Caused by Dominant Alleles on Autosomes

    • Huntington's disease (affects nervous system) is a dominant trait.
    • When the affected allele is present, the phenotype will be affected

    Expression of Sex-Linked Genes

    • Males express recessive sex-linked genes.
    • Males cannot be carriers of X-linked diseases.

    Sex-Linked Disease Example

    • Color blindness and hemophilia are examples of X-linked recessive traits.
    • Rett syndrome is an X-linked dominant trait.

    Incomplete Dominance

    • Defined: Neither allele is completely dominant.
    • Heterozygous traits show a blended phenotype.
    • Multiple phenotypes are possible.
    • An example is flower color.

    Codominance

    • Codominant alleles are fully expressed.
    • They are neither dominant nor recessive.
    • Blood types are an example of codominance.

    Polygenic Traits

    • Multiple genes interact to create a trait.
    • Human skin color and eye color are examples.

    Epistasis

    • One gene can overshadow others.
    • Epistatic gene interferes with other genes' expression (e.g., controlling pigment production).
    • Mouse fur and albinism are examples of epistasis.

    The Environment and Phenotype

    • Phenotype is influenced by both genotype and environment.
    • Environmental factors can alter a trait (like sunlight lightening hair).
    • Sea turtle sex is influenced by incubation temperature.

    Practice Problems:

    • Specific questions and answers are given for practical examples of trait inheritance patters, including problems regarding genetic disorders, predicting offspring genotypes in cross breeding cases, and using Punnett squares are provided
    • Various alleles and inheritance patterns are illustrated in practice questions and answers, such as those related to hemophilia, color blindness, practice pedigrees and more intricate inheritance patterns such as polygenic traits and epistatic interactions.

    Gene Linkage and Mapping

    • Linked genes are on the same chromosome.
    • Often inherited together, but not always.
    • Crossing over breaks up linkages during meiosis.
    • Linkage maps display gene locations relative to each other. This is influenced by the frequency on crossing over events.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Chromosomes and Phenotype Presentation PDF

    Description

    Test your knowledge on autosomal recessive disorders and inheritance patterns. This quiz covers essential concepts such as genetic notation, examples of disorders, and the characteristics of genetic traits. Challenge yourself to match disorders with their inheritance types and calculate probabilities related to these genetic traits.

    More Like This

    Autosomal Recessive Inheritance Disorders Quiz
    77 questions

    Autosomal Recessive Inheritance Disorders Quiz

    UserFriendlyIntelligence avatar
    UserFriendlyIntelligence
    Genetic Disorders Quiz
    30 questions

    Genetic Disorders Quiz

    RobustPhotorealism avatar
    RobustPhotorealism
    Gilbert Syndrome: Autosomal Dominant/Recessive Trait
    28 questions

    Gilbert Syndrome: Autosomal Dominant/Recessive Trait

    HealthyArlington7782 avatar
    HealthyArlington7782
    Cystic Fibrosis and Autosomal Recessive Genetics
    15 questions

    Cystic Fibrosis and Autosomal Recessive Genetics

    InterestingAndradite avatar
    InterestingAndradite
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser