Test Bank For Medical Genetics 6th Edition
By Authors: Lynn B. Jorde, John C. Carey, Michael J. Bamshad
@2024
,Chapter 1 - Background and History
1. Which of the following are examples of Mendelian inheritance? (Select all that apply)
A) Cystic fibrosis
B) Down syndrome
C) Hemophilia A
D) Huntington's disease
E) Turner syndrome
Answer: A, C, D
Rationale: Mendelian inheritance refers to single-gene disorders inherited in a dominant,
recessive, or X-linked pattern. Cystic fibrosis (autosomal recessive), Hemophilia A (X-linked
recessive), and Huntington's disease (autosomal dominant) are examples of Mendelian
inheritance. Down syndrome (chromosomal abnormality) and Turner syndrome (chromosomal
condition) are not.
NCLEX preference: Test-takers must understand genetic inheritance patterns and differentiate
between Mendelian and non-Mendelian conditions.
2. What is the significance of Gregor Mendel’s contribution to genetics?
A) Discovered DNA as the genetic material
B) Established the principles of inheritance
C) Mapped the human genome
D) Discovered the double-helix structure of DNA
Answer: B
Rationale: Gregor Mendel, known as the "Father of Genetics," established the principles of
inheritance (dominant and recessive traits) through his work with pea plants. Options A, C, and
D are associated with later discoveries in genetics.
NCLEX preference: Basic understanding of foundational genetic principles is required.
3. A patient has a family history of Huntington's disease, which is an autosomal dominant
condition. What is the chance that this patient will inherit the disorder if one parent is
affected?
A) 100%
B) 50%
C) 25%
D) 0%
Answer: B
Rationale: In autosomal dominant inheritance, there is a 50% chance of passing the affected
allele from an affected parent to a child. Each child has an independent 1 in 2 chance of
inheriting the disorder.
NCLEX preference: Recognizing inheritance risks in genetic counseling is vital for nurses.
,4. Which of the following is a hallmark of X-linked recessive inheritance?
A) Equal incidence in males and females
B) Higher incidence in males than females
C) Direct father-to-son transmission
D) All children of affected mothers will inherit the disorder
Answer: B
Rationale: X-linked recessive disorders primarily affect males, as they only have one X
chromosome. Fathers cannot pass X-linked recessive conditions to their sons, and not all
children of affected mothers will inherit the disorder unless the father is also affected.
NCLEX preference: Understanding X-linked inheritance patterns helps in clinical assessments
and patient education.
5. Which genetic disorder is most commonly associated with non-disjunction during
meiosis?
A) Cystic fibrosis
B) Down syndrome
C) Marfan syndrome
D) Sickle cell anemia
Answer: B
Rationale: Down syndrome is commonly caused by non-disjunction during meiosis, resulting in
an extra chromosome 21. The other disorders listed are caused by gene mutations, not
chromosomal abnormalities.
NCLEX preference: Nurses must identify the cause of chromosomal disorders and recognize
their clinical implications.
6. What does the term "genotype" refer to in genetics?
A) The observable physical traits of an individual
B) The location of a gene on a chromosome
C) The genetic makeup of an individual
D) The process of gene mutation
Answer: C
Rationale: Genotype refers to the genetic constitution of an individual, i.e., the alleles present at
a particular locus or loci. The phenotype refers to the observable traits.
NCLEX preference: Definitions of key genetic terms are crucial for test-takers.
7. In mitochondrial inheritance, which of the following statements is true?
A) Mitochondrial DNA is inherited equally from both parents
B) Only males can pass mitochondrial DNA to offspring
, C) Only females pass mitochondrial DNA to their children
D) Mitochondrial disorders are caused by mutations in nuclear DNA
Answer: C
Rationale: Mitochondrial DNA is inherited exclusively from the mother. Both male and female
offspring can inherit the mitochondrial DNA, but only females pass it on.
NCLEX preference: Nurses should understand maternal inheritance patterns in genetic
diseases.
8. Which of the following best describes the Human Genome Project?
A) A project focused on creating synthetic genomes
B) A research initiative to identify all the genes in human DNA
C) A project aimed at identifying genetic mutations in cancer
D) A clinical trial for gene therapy
Answer: B
Rationale: The Human Genome Project was an international research initiative with the goal of
mapping all human genes and understanding their functions.
NCLEX preference: Familiarity with major advances in genetics is essential for modern
healthcare practice.
9. In autosomal recessive inheritance, if both parents are carriers, what is the probability
that their child will express the disorder?
A) 25%
B) 50%
C) 75%
D) 100%
Answer: A
Rationale: In autosomal recessive inheritance, when both parents are carriers, there is a 25%
chance that their child will inherit two copies of the mutated gene and express the disorder.
NCLEX preference: Understanding inheritance patterns is key for nurses in genetic counseling.
10. Which of the following historical milestones is associated with the discovery of DNA's
double-helix structure?
A) Gregor Mendel's experiments
B) The Human Genome Project
C) Watson and Crick's work
D) The discovery of X-linked inheritance
Answer: C
Rationale: James Watson and Francis Crick are credited with discovering the double-helix
structure of DNA in 1953.
By Authors: Lynn B. Jorde, John C. Carey, Michael J. Bamshad
@2024
,Chapter 1 - Background and History
1. Which of the following are examples of Mendelian inheritance? (Select all that apply)
A) Cystic fibrosis
B) Down syndrome
C) Hemophilia A
D) Huntington's disease
E) Turner syndrome
Answer: A, C, D
Rationale: Mendelian inheritance refers to single-gene disorders inherited in a dominant,
recessive, or X-linked pattern. Cystic fibrosis (autosomal recessive), Hemophilia A (X-linked
recessive), and Huntington's disease (autosomal dominant) are examples of Mendelian
inheritance. Down syndrome (chromosomal abnormality) and Turner syndrome (chromosomal
condition) are not.
NCLEX preference: Test-takers must understand genetic inheritance patterns and differentiate
between Mendelian and non-Mendelian conditions.
2. What is the significance of Gregor Mendel’s contribution to genetics?
A) Discovered DNA as the genetic material
B) Established the principles of inheritance
C) Mapped the human genome
D) Discovered the double-helix structure of DNA
Answer: B
Rationale: Gregor Mendel, known as the "Father of Genetics," established the principles of
inheritance (dominant and recessive traits) through his work with pea plants. Options A, C, and
D are associated with later discoveries in genetics.
NCLEX preference: Basic understanding of foundational genetic principles is required.
3. A patient has a family history of Huntington's disease, which is an autosomal dominant
condition. What is the chance that this patient will inherit the disorder if one parent is
affected?
A) 100%
B) 50%
C) 25%
D) 0%
Answer: B
Rationale: In autosomal dominant inheritance, there is a 50% chance of passing the affected
allele from an affected parent to a child. Each child has an independent 1 in 2 chance of
inheriting the disorder.
NCLEX preference: Recognizing inheritance risks in genetic counseling is vital for nurses.
,4. Which of the following is a hallmark of X-linked recessive inheritance?
A) Equal incidence in males and females
B) Higher incidence in males than females
C) Direct father-to-son transmission
D) All children of affected mothers will inherit the disorder
Answer: B
Rationale: X-linked recessive disorders primarily affect males, as they only have one X
chromosome. Fathers cannot pass X-linked recessive conditions to their sons, and not all
children of affected mothers will inherit the disorder unless the father is also affected.
NCLEX preference: Understanding X-linked inheritance patterns helps in clinical assessments
and patient education.
5. Which genetic disorder is most commonly associated with non-disjunction during
meiosis?
A) Cystic fibrosis
B) Down syndrome
C) Marfan syndrome
D) Sickle cell anemia
Answer: B
Rationale: Down syndrome is commonly caused by non-disjunction during meiosis, resulting in
an extra chromosome 21. The other disorders listed are caused by gene mutations, not
chromosomal abnormalities.
NCLEX preference: Nurses must identify the cause of chromosomal disorders and recognize
their clinical implications.
6. What does the term "genotype" refer to in genetics?
A) The observable physical traits of an individual
B) The location of a gene on a chromosome
C) The genetic makeup of an individual
D) The process of gene mutation
Answer: C
Rationale: Genotype refers to the genetic constitution of an individual, i.e., the alleles present at
a particular locus or loci. The phenotype refers to the observable traits.
NCLEX preference: Definitions of key genetic terms are crucial for test-takers.
7. In mitochondrial inheritance, which of the following statements is true?
A) Mitochondrial DNA is inherited equally from both parents
B) Only males can pass mitochondrial DNA to offspring
, C) Only females pass mitochondrial DNA to their children
D) Mitochondrial disorders are caused by mutations in nuclear DNA
Answer: C
Rationale: Mitochondrial DNA is inherited exclusively from the mother. Both male and female
offspring can inherit the mitochondrial DNA, but only females pass it on.
NCLEX preference: Nurses should understand maternal inheritance patterns in genetic
diseases.
8. Which of the following best describes the Human Genome Project?
A) A project focused on creating synthetic genomes
B) A research initiative to identify all the genes in human DNA
C) A project aimed at identifying genetic mutations in cancer
D) A clinical trial for gene therapy
Answer: B
Rationale: The Human Genome Project was an international research initiative with the goal of
mapping all human genes and understanding their functions.
NCLEX preference: Familiarity with major advances in genetics is essential for modern
healthcare practice.
9. In autosomal recessive inheritance, if both parents are carriers, what is the probability
that their child will express the disorder?
A) 25%
B) 50%
C) 75%
D) 100%
Answer: A
Rationale: In autosomal recessive inheritance, when both parents are carriers, there is a 25%
chance that their child will inherit two copies of the mutated gene and express the disorder.
NCLEX preference: Understanding inheritance patterns is key for nurses in genetic counseling.
10. Which of the following historical milestones is associated with the discovery of DNA's
double-helix structure?
A) Gregor Mendel's experiments
B) The Human Genome Project
C) Watson and Crick's work
D) The discovery of X-linked inheritance
Answer: C
Rationale: James Watson and Francis Crick are credited with discovering the double-helix
structure of DNA in 1953.
