Genetics and Inheritance Patterns (Easy)
24 Questions
3 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 term for when a dominant allele is not expressed even though an individual carries it?

  • Dominance
  • Overdominance
  • Incomplete dominance
  • Penetrance (correct)

    • What is the result of a cross between homozygous red-flowered and homozygous white-flowered parents?

  • Homozygous offspring with red or white flowers
  • Heterozygous offspring with red flowers
  • Heterozygous offspring with white flowers
  • Heterozygous offspring with pink flowers (correct)

    • Why does a heterozygote not express the same trait as a homozygote?

  • Because the dominant allele is not present
  • Because the protein produced by the functional allele is not sufficient (correct)
  • Because the recessive allele is dominant
  • Because of environmental influences

    • What is the term for when a heterozygote has a trait that is more beneficial than either homozygote?

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

    What is an example of a dominant trait that is not expressed?

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

    What is the term for when the heterozygote expresses both alleles simultaneously without forming an intermediate phenotype?

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

    Why may a heterozygote have increased resistance to infection by microorganisms?

    <p>Because their cells may have increased resistance to infection</p> Signup and view all the answers

    What is the result of molecular interactions between proteins encoded by different alleles?

    <p>Enhanced function of protein dimers</p> Signup and view all the answers

    What is the primary focus of the chapter on extensions of Mendelian inheritance?

    <p>Traits that deviate from the simple dominant/recessive relationship</p> Signup and view all the answers

    What is the relationship between the molecular expression of a gene and the trait itself?

    <p>The relationship is complex and depends on the specific gene</p> Signup and view all the answers

    What is the definition of simple Mendelian inheritance?

    <p>A single gene with two different alleles</p> Signup and view all the answers

    What is the purpose of examining different patterns of Mendelian inheritance?

    <p>Both a and b</p> Signup and view all the answers

    What is the blood type of an individual carrying the A and B alleles?

    <p>AB blood type</p> Signup and view all the answers

    What is the term applied to the inheritance of alleles that obey Mendel's laws?

    <p>Mendelian inheritance</p> Signup and view all the answers

    What is an example of genetic polymorphism?

    <p>A single gene with three or more alleles</p> Signup and view all the answers

    What is the characteristic of codominant alleles?

    <p>Both alleles encode proteins that function slightly differently</p> Signup and view all the answers

    What is the result of 50% of the protein produced by a single copy of the dominant allele in the heterozygote?

    <p>The dominant trait is expressed</p> Signup and view all the answers

    In which type of inheritance pattern do males have one copy of genes and females have two copies?

    <p>X-linked inheritance</p> Signup and view all the answers

    What is the focus of Table 4.1?

    <p>Mendelian inheritance patterns involving single genes</p> Signup and view all the answers

    What is the effect of sex hormones on the molecular expression of genes in sex-influenced inheritance?

    <p>They regulate the expression of genes</p> Signup and view all the answers

    What is an example of a sex-limited trait?

    <p>Breast development in mammals</p> Signup and view all the answers

    What is the relationship between X-linked alleles in a heterozygous female?

    <p>The alleles show a simple dominant/recessive relationship</p> Signup and view all the answers

    What is the effect of a single copy of a dominant X-linked allele in a heterozygous female?

    <p>It produces a dominant trait</p> Signup and view all the answers

    In which type of inheritance pattern do sex hormones regulate the molecular expression of genes?

    <p>Sex-influenced inheritance</p> Signup and view all the answers

    Study Notes

    Inheritance Patterns

    • Incomplete Penetrance: A dominant allele is present, but its effects are not seen due to environmental influences or counteracting proteins from other genes.

    Incomplete Dominance

    • A heterozygote has a phenotype that is intermediate between the two corresponding homozygotes, e.g., a cross between red-flowered and white-flowered parents produces pink-flowered offspring.

    Overdominance

    • A heterozygote has a trait that is more beneficial than either homozygote.
    • Three ways heterozygotes gain benefits:
      • Increased resistance to infection by microorganisms
      • Producing more forms of protein dimers with enhanced function
      • Producing proteins that function under a wider range of conditions

    Extensions of Mendelian Inheritance

    • Mendelian inheritance describes patterns that obey two laws: the Law of Segregation and the Law of Independent Assortment.
    • Simple Mendelian inheritance involves a single gene with two different alleles that display a simple dominant/recessive relationship.

    Codominance

    • The codominant alleles encode proteins that function slightly differently from each other, and the function of each protein in the heterozygote affects the phenotype uniquely.
    • Example: blood typing, where an individual carrying the A and B alleles will have an AB blood type.

    X-linked Inheritance

    • Inheritance of genes located on the X chromosome.
    • In mammals and fruit flies, males have one copy of X-linked genes, whereas females have two copies.
    • If a pair of X-linked alleles shows a simple dominant/recessive relationship, 50% of the protein produced by a single copy of the dominant allele in a heterozygous female is sufficient to produce the dominant trait.

    Sex-influenced Inheritance

    • The effect of sex on the phenotype of an individual.
    • Some alleles are recessive in one sex and dominant in the opposite sex.
    • Sex hormones may regulate the molecular expression of genes, influencing the phenotypic effects of alleles.

    Sex-limited Inheritance

    • Traits that occur in only one of the two sexes.
    • Example: breast development in mammals.
    • Sex hormones that are primarily produced in only one sex are essential to produce a particular phenotype.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Lecture 2 Extensions of Mendelian Inheritance PDF

    Description

    This quiz covers concepts related to inheritance patterns, including penetrance and molecular influences on gene expression. It explores how dominant traits can be affected by environmental factors and more.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser