Exam - Genetics - Inheritance Patterns

30 Questions | Total Attempts: 111

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Exam - Genetics - Inheritance Patterns

Questions and Answers
  • 1. 
    In humans, pigmented skin is dominant to non-pigmented skin (albinism). What is the genotype of an individual with albinism?
    • A. 

      Carrier

    • B. 

      Heterozygous

    • C. 

      Homozygous dominant

    • D. 

      Homozygous recessive

  • 2. 
    Adrenoleukodystrophy (ALD) is a sex-linked recessive trait that affects the nervous system. In one family, the father, mother, daughter, and elder son do not have ALD, while the younger son has ALD. Who must be a carrier of the ALD allele?
    • A. 

      Father

    • B. 

      Mother

    • C. 

      Daughter

    • D. 

      Elder son

  • 3. 
    Cystic fibrosis is a genetic disease in which excess mucus accumulates in the lungs and digestive system of affected individuals. Males and females must inherit 2 of the same alleles with this mutation to have the disease. What is the mode of inheritance of cystic fibrosis?
    • A. 

      Autosomal dominant

    • B. 

      Autosomal recessive

    • C. 

      Sex-linked dominant

    • D. 

      Sex-linked recessive

  • 4. 
    Which event of meiosis reveals the mechanism for understanding Mendel’s laws of segregation and independent assortment?
    • A. 

      Chromosome number is reduced during telophase I so gametes have half the standard number of chromosomes.

    • B. 

      The arrangement of homologous chromosomes during metaphase I varies from cell to cell.

    • C. 

      Centromeres break apart during anaphase II so that sister chromatids can move to opposite poles of the cell.

    • D. 

      DNA is replicated during interphase before chromosomes condense and become attached to kinetochores.

  • 5. 
    Two black guinea pigs bred and produced 3 black offspring and 2 albino offspring. Assuming no mutations, which guinea pigs must be heterozygous?        
    • A. 

      All 3 black offspring

    • B. 

      Exactly 2 of the black offspring Exactly 2 of the black offspring Exactly 2 of the black offspring Exactly 2 of the black offspring

    • C. 

      Both albino offspring

    • D. 

      Both parents

  • 6. 
    The genotype of F1 individuals from a dihybrid cross is AaBb x AaBB. What is the expected ratio of AaBb individuals in the F2 generation?
    • A. 

      8/16

    • B. 

      4/16

    • C. 

      2/16

    • D. 

      1/16

  • 7. 
    Alkaptonuria is a genetic disorder of protein metabolism.  The disorder is determined by 2 alleles at 1 locus. What is the genotype for Individual 1 in the diagram?
    • A. 

      AA or Aa

    • B. 

      AA

    • C. 

      Aa

    • D. 

      Aa

  • 8. 
    A trisomy of chromosome 21 causes what condition?
    • A. 

      Albinism

    • B. 

      Dwarfism

    • C. 

      Down syndrome

    • D. 

      Color blindness

  • 9. 
    Keisha passes a local dairy farm that has many brown cows, but only a few white cows. A dominant allele produces brown hair in cows and a recessive allele produces white hair. Which characteristic of any brown cow can Keisha identify?
    • A. 

      The genotype of both of the cow’s parents

    • B. 

      The genotype of the cow’s hair color

    • C. 

      The phenotype of both of the cow’s parents

    • D. 

      The phenotype of the cow’s hair color

  • 10. 
    Jeanine inherited 2 alleles for round eye shape and has round eye shape. Her brother inherited 1 allele for round eye shape and 1 allele for almond eye shape and has almond eye shape. What type of trait is round eye shape?
    • A. 

      Co-dominant

    • B. 

      Dominant

    • C. 

      Recessive

    • D. 

      Sex-linked

  • 11. 
    In humans, red-green color blindness is a recessive, sex-linked trait. The chromosomes and alleles associated with color blindness are represented in this chart. Which child could NOT be born to these parents; a female (XBXb) and a male (XBY)?
    • A. 

      Color-blind daughter

    • B. 

      Color-blind son

    • C. 

      Daughter with normal color vision

    • D. 

      Son with normal color vision

  • 12. 
    The pedigree shows 3 generations of a family and the family’s incidences of color blindness, a sex-linked, recessive trait. Which pair of females must have the same genotype?
    • A. 

      3 and 5

    • B. 

      7 and 11

    • C. 

      8 and 13

    • D. 

      10 and 14

  • 13. 
    Which example best illustrates Mendel’s law of independent assortment?
    • A. 

      Two short-haired cats produce a litter of 4 kittens including 1 long-haired and 3 short-haired.

    • B. 

      A color-blind man and a woman with normal vision produce a son with normal vision and a color-blind daughter.

    • C. 

      A tall purple-flowered pea plant and a short white-flowered pea plant are crossed, producing offspring including tall white-flowered pea plants.

    • D. 

      A red-flowered snapdragon and a white-flowered snapdragon are crossed, producing offspring with pink flowers.

  • 14. 
    Horses born to 2 palomino (golden-coated) horses have a 25% chance of having a white coat, a 25% chance of having a chestnut (brown) coat, and a 50% chance of having a palomino coat. Which description of inheritance best explains the coat-color trait in these horses?
    • A. 

      Palomino coat color is a recessive trait.

    • B. 

      Palomino coat color is a dominant trait.

    • C. 

      Coat color is an incompletely dominant trait.

    • D. 

      Coat color is a sex-linked trait.

  • 15. 
    The X and Y chromosomes are called the
    • A. 

      Extra chromosomes.

    • B. 

      Phenotypes.

    • C. 

      Sex chromosomes.

    • D. 

      All of the above.

  • 16. 
    Which of the following is the best explanation for the observation that females rarely get the disease hemophilia?
    • A. 

      Large quantities of male hormones are necessary in order for the allele carrying the disease to be expressed.

    • B. 

      Female fetuses that carry the allele for the disease die before birth.

    • C. 

      A female could get the disease only by having a mother who is a carrier and a father who has the disease. Since most males with the disease do not survive to reproductive age, this is an extremely unlikely event.

    • D. 

      A female could get the disease only by having parents who are both carriers of the disease. Because females cannot be carriers, this is an impossible event.

  • 17. 
    In a mating between two parental types, one of which is homozygous dominant for two linked traits and one of which is homozygous recessive for the same two linked traits, evidence of crossing-over would be apparent in which of the following generations?
    • A. 

      Parents

    • B. 

      F1

    • C. 

      F2

    • D. 

      All of the above

  • 18. 
    Which of the following traits is controlled by multiple alleles in humans?
    • A. 

      Sickle cell anemia

    • B. 

      Blood type

    • C. 

      Hemophilia

    • D. 

      Pattern baldness

  • 19. 
    What would be the blood type of a person who inherited an A allele from one parent and an O allele from the other?
    • A. 

      Type A

    • B. 

      Type B

    • C. 

      Type AB

    • D. 

      Type O

  • 20. 
    While studying several generations of a particular family, a geneticist observed that a certain disease was found equally in males and females and that all children who had the disease had parents who also had the disease. The gene coding for this disease is probably
    • A. 

      Sex-linked recessive.

    • B. 

      Sex-linked dominant.

    • C. 

      Autosomal recessive.

    • D. 

      Autosomal dominant.

  • 21. 
    If both parents carry the recessive allele that causes cystic fibrosis, the chance that their child will develop the disease is
    • A. 

      One in two.

    • B. 

      One in four.

    • C. 

      Two in five.

    • D. 

      100%.

  • 22. 
    If a characteristic is sex-linked, it
    • A. 

      Occurs most commonly in males.

    • B. 

      Occurs only in females.

    • C. 

      Can never occur in females.

    • D. 

      Is always fatal.

  • 23. 
    Since the allele for colorblindness is located on the X chromosome, colorblindness
    • A. 

      Cannot be inherited.

    • B. 

      Occurs only in adults.

    • C. 

      Is sex-linked.

    • D. 

      None of the above.

  • 24. 
    The sex of an offspring is determined by
    • A. 

      The mother.

    • B. 

      The father.

    • C. 

      Both parents.

    • D. 

      The offspring.

  • 25. 
    When Gregor Mendel crossed true-breeding tall plants with true-breeding short plants, all the offspring were tall because
    • A. 

      The allele for tall plants is recessive.

    • B. 

      The allele for short plants is dominant.

    • C. 

      The allele for tall plants is dominant.

    • D. 

      They were true-breeding like their parents.

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