Block 7 Repro Genetics MCQ's Prt 2

16 Questions | Total Attempts: 177

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Block 7 Repro Genetics MCQ

Questions and Answers
  • 1. 
    In last century, several countries instituted policies where sterilization was forced on, for example, people with mental retardation. In addition to this being ethically questionable, it was also wrong because:  
    • A. 

      Most of the cases caused by dominant diseases come from new mutations

    • B. 

      Most of the cases caused by autosomal recessive genes are due to new mutations

    • C. 

      Most dominant alleles are hidden in heterozygotes

    • D. 

      The recessive alleles lost are insignificant compared to those hidden in heterozygotes

    • E. 

      The phenotypes is a side effect of elements that are beneficial to mankind

  • 2. 
    Which statement is a prediction of the multifactorial threshold model?
    • A. 

      An individual's risk is not altered by the number of affected first-degree relatives

    • B. 

      The age of onset decreases when there are affected relatives in two previous generations

    • C. 

      The differential risk to relatives of an affected proband increases as the disease prevalence decreases

    • D. 

      Affected individuals almost always have an affected parent

  • 3. 
    Which of the following observations is the strongest evidence for an important genetic component in the causation of type-1 diabetes mellitus (IDDM)?
    • A. 

      Pancreatic b-cell autoantibodies are frequently present

    • B. 

      Approximately 10% of affected indivifuals have an affected sibling

    • C. 

      Onset of disease is usually in childhood.

    • D. 

      The concordance rate in monozygotic twins is approximately 30%.

    • E. 

      The concordance rate in monozygotic twins is five times that in dizygotic twins.

  • 4. 
    The average recurrence risk for a couple that has had a child with cleft lip, a multifactorial birth defect, is approximately 4%. What is the recurrence risk if the couple has two affected children?
    • A. 

      2%

    • B. 

      4%

    • C. 

      10%

    • D. 

      25%

    • E. 

      50%

  • 5. 
    Given that G (effect due to genetics) = 0.50, E1 (effect due to individual differences) = 0.10, and E2 (effect due to familial differences) = 0.40, which of the following pairs of individuals will be most similar in ability to score high on an IQ test.
    • A. 

      Siblings reared apart

    • B. 

      Grandson - grandfather

    • C. 

      Dizygotic twins reared together

    • D. 

      Monozygotic twins reared apart

  • 6. 
    Given 1 locus with 2 alleles that are strictly additive, the additive genetic variance (2pqa^2) is at a maximum when
    • A. 

      Q = 0.5

    • B. 

      Q = 1.0

    • C. 

      Q = 0.0

    • D. 

      P = 0.25

  • 7. 
    In a population of flies the mean bristle number was 6.4. Three pairs of flies were used as parents and their mean bristle number was 7.2. Their offspring had a mean bristle number of 7.0. What was the realized heritability?
    • A. 

      0.75

    • B. 

      0.25

    • C. 

      0.91

    • D. 

      0.86

  • 8. 
    A measure of dispersion about the mean in a population is the
    • A. 

      Covariance

    • B. 

      Average

    • C. 

      Correlation

    • D. 

      Variance

  • 9. 
    At the D locus, there are two alleles with "D" incompletely dominant to "d". Population A has a frequency of the "D" allele equal to 0.6 (p = 0.6), while population B has a frequency of the "D" allele equal to 0.8 (p = 0.8). Which of the following statements is true?
    • A. 

      Va is greater in population B

    • B. 

      Va is greater in population A

    • C. 

      Va is equal in both populations

    • D. 

      No conclusion can be drawn about the variance of either population.

  • 10. 
    To determine if there is a relationship between two variables such that as one variable changes the other also changes, we would calculate a
    • A. 

      Variance

    • B. 

      Standard error

    • C. 

      Correlation coefficient

    • D. 

      Coefficient of variation

  • 11. 
    In the P generation we crossed a red-flowered and white-flowered plant to get an F1 generation that was intermediate in color (pink) between the two parents. The F1s were then crossed to produce an F2. Which of the following will have the largest phenotypic variance?
    • A. 

      The red-flowered P generation

    • B. 

      The white-flowered P generation

    • C. 

      The F1 generation

    • D. 

      The F2 generation

  • 12. 
    Which of the following statements about Hirschsprung disease is incorrect?
    • A. 

      It shows an association with Down syndrome.

    • B. 

      It is more common in girls than in boys.

    • C. 

      RET is a major susceptibility gene

    • D. 

      Recurrence risks are greater for long segment disease than for short segment disease.

  • 13. 
    Which of the following conditions does not show multifactorial inheritance?
    • A. 

      Pyloric stenosis

    • B. 

      Schizophrenia

    • C. 

      Spina bifida (neural tube defects)

    • D. 

      Marfan syndrome

  • 14. 
    In a condition such as schizophrenia the recurrence risk will be greatest for which of the following relatives of an affected individual?
    • A. 

      Brother

    • B. 

      Nephew

    • C. 

      Grandchild

    • D. 

      Aunt

  • 15. 
    Imagine a species of Giraffes living on the savanna in Africa. The overall size of these varies as expected for a quantitative trait. The smallest giraffes have difficulty surviving, because they cannot reach the leafs on the trees that this species feed on. The largest giraffes have difficulty growing muscle large enough to move the massive bones needed for supporting this size of an animal. Therefore, the giraffes closest to the average size stand the best chance of surviving and reproducing. This is an example of which special concept?
    • A. 

      Stabilizing selection

    • B. 

      Disruptive selection

    • C. 

      Directional selection

    • D. 

      Founder effect

    • E. 

      Genetic drift

  • 16. 
    If you have high cholesterol, you may consider taking statins to help lower the levels. If you have desirable alleles in both the cholesteryl ester transfer protein and multidrug resistance transporter genes, the statin Fluvostatin will work well. However, if you have only undesirable alleles in both genes you will want to avoid Fluvostatin. If you have a mixture of desirable and undesirable alleles, then the number of each will determine the outcome. This description best fit which of the following concepts?
    • A. 

      Assortative mating

    • B. 

      Allele sharing

    • C. 

      Additive effects

    • D. 

      Low heritability

    • E. 

      Anticipation

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