GN 301 EXAM 3 UPDATED QUESTIONS AND CORRECT
ANSWERS
Question:
1. Quantitative traits characteristics
Answer:
- Many genes control the trait
- Effect of each gene is small
- Effects of genes add together
- The environment also influences the pheno-
type
- Underlying discrete genotypic distribution,
but appears as a normal phenotypic distribu-tion due to the environmental effects.
Question:
2. Threshold traits
Answer:
problems involving additive effects of alleles
Question:
3. Select all that must be satisfied in order for a population to be at Hardy-Weinberg Equilibrium.
Question 3Select one or more:a. Selection does not occur b. Related individuals marry c. The
population is panmictic d. Mutation does not occur e. Migration does not occur f. The population is
infinitely large g. p = q = 0.5 h. Genetic drift occurs
Answer:
Selection does not occur, The population is infinitely large, Migration does not occur, The population
is panmictic, Mutation does not oc-cur
Question:
4. The type of selection that favors het-erozygous individuals over homozygous individuals is called
Answer:
Stabilizing Selection
Question:
5. Mark all that are true about consan-guineous unions. Question 10Select one or more:a. Increases
the frequency of recessive alle-les b. Increases the frequency of recessive phe-notypes c. Decreases
the proportion of heterozy-gous individuals in the population d. Increases the proportion of
homozygous genotypes e. Decreases the frequency of recessive phenotypes Feedback
Answer:
Decreases the proportion of heterozygous in-dividuals in the population, Increases the fre-quency of
recessive phenotypes, Increases the proportion of homozygous genotypes
Question:
6. Which two types of human DNA are most frequently studied when determin-ing evolutionary
relationships?
Answer:
Y Chromosome, Mitochondrial DNA
, Question:
7. The type of selection that favors one ho-mozygous type and is least favorable for the other
homozygous type is
Answer:
Directional Selection
Question:
8. The type of selection in which both ho-mozygous types are favored over the het-erozygous type is
called
Answer:
Disruptive Selection
Question:
9. Which is NOT a benefit of genetic coun-seling?
Question 1Select one:a.
Fixes all medical problems of the patient b.
Provides an explanation and relief from uncertainty c.
Helps inform decisions about managing healthcare d.
Assists in getting services covered e.
Offers information for family members f.
Aids in planning for the future
Answer:
Fixes all medical problems of the patient
Question:
10. Which is NOT a common indication for referral to genetic counseling?
Question 2Select one:a.
Unexplained intellectual and/or develop-mental delay b.
Recurrent pregnancy loss c.
Suspected genetic condition d.
Mother greater or equal to 25 years old at delivery e.
Non-familial dysmorphic features f.
Birth defects g.
Abnormal newborn screening
Answer:
Mother greater or equal to 25 years old at delivery
Question:
11. Angelman Syndrome is usually due to a .....
Answer:
Deletion of part of chromosome # 15 including the UBE3A gene
Question:
12. Cri du chat is ....
Answer:
Usually a de novo (sporatic) event
ANSWERS
Question:
1. Quantitative traits characteristics
Answer:
- Many genes control the trait
- Effect of each gene is small
- Effects of genes add together
- The environment also influences the pheno-
type
- Underlying discrete genotypic distribution,
but appears as a normal phenotypic distribu-tion due to the environmental effects.
Question:
2. Threshold traits
Answer:
problems involving additive effects of alleles
Question:
3. Select all that must be satisfied in order for a population to be at Hardy-Weinberg Equilibrium.
Question 3Select one or more:a. Selection does not occur b. Related individuals marry c. The
population is panmictic d. Mutation does not occur e. Migration does not occur f. The population is
infinitely large g. p = q = 0.5 h. Genetic drift occurs
Answer:
Selection does not occur, The population is infinitely large, Migration does not occur, The population
is panmictic, Mutation does not oc-cur
Question:
4. The type of selection that favors het-erozygous individuals over homozygous individuals is called
Answer:
Stabilizing Selection
Question:
5. Mark all that are true about consan-guineous unions. Question 10Select one or more:a. Increases
the frequency of recessive alle-les b. Increases the frequency of recessive phe-notypes c. Decreases
the proportion of heterozy-gous individuals in the population d. Increases the proportion of
homozygous genotypes e. Decreases the frequency of recessive phenotypes Feedback
Answer:
Decreases the proportion of heterozygous in-dividuals in the population, Increases the fre-quency of
recessive phenotypes, Increases the proportion of homozygous genotypes
Question:
6. Which two types of human DNA are most frequently studied when determin-ing evolutionary
relationships?
Answer:
Y Chromosome, Mitochondrial DNA
, Question:
7. The type of selection that favors one ho-mozygous type and is least favorable for the other
homozygous type is
Answer:
Directional Selection
Question:
8. The type of selection in which both ho-mozygous types are favored over the het-erozygous type is
called
Answer:
Disruptive Selection
Question:
9. Which is NOT a benefit of genetic coun-seling?
Question 1Select one:a.
Fixes all medical problems of the patient b.
Provides an explanation and relief from uncertainty c.
Helps inform decisions about managing healthcare d.
Assists in getting services covered e.
Offers information for family members f.
Aids in planning for the future
Answer:
Fixes all medical problems of the patient
Question:
10. Which is NOT a common indication for referral to genetic counseling?
Question 2Select one:a.
Unexplained intellectual and/or develop-mental delay b.
Recurrent pregnancy loss c.
Suspected genetic condition d.
Mother greater or equal to 25 years old at delivery e.
Non-familial dysmorphic features f.
Birth defects g.
Abnormal newborn screening
Answer:
Mother greater or equal to 25 years old at delivery
Question:
11. Angelman Syndrome is usually due to a .....
Answer:
Deletion of part of chromosome # 15 including the UBE3A gene
Question:
12. Cri du chat is ....
Answer:
Usually a de novo (sporatic) event