Deck 4: Genes and Genetic Diseases

Question 1

What is the most common cause of Down syndrome?

A) Paternal nondisjunction
B) Maternal translocations
C) Maternal nondisjunction
D) Paternal translocation

Answer 1

Maternal nondisjunction

Question 2

What syndrome,characterized by an absent homologous X chromosome with only a single X chromosome,exhibits features that include a short stature,widely spaced nipples,and webbed neck?

A) Down
B) Cri du chat
C) Turner
D) Klinefelter

Answer 2

Turner

Question 3

The most clinically useful technique for prenatal diagnosis of chromosomal abnormalities at 3 months' (12 weeks')gestation is:

A) Gene mapping
B) Linkage analysis
C) Amniocentesis
D) Chorionic villus sampling

Answer 3

Chorionic villus sampling

Question 4

What is the blood type of a person who is heterozygous,having A and B alleles as codominant?

A) A
B) B
C) O
D) AB

Question 5

The term for an error in which homologous chromosomes fail to separate during meiosis or mitosis is:

A) Aneuploidy
B) Nondisjunction
C) Polyploidy
D) Translocation

Question 6

Which clinical manifestations would be expected for a child who has complete trisomy of the twenty-first chromosome?

A) Widely spaced nipples, reduced carrying angle at the elbow, and sparse body hair
B) An IQ of 25 to 70, low nasal bridge, protruding tongue, and flat, low-set ears
C) High-pitched voice, tall stature, gynecomastia, and an IQ of 60 to 90
D) Circumoral cyanosis, edema of the feet, short stature, and mental slowness

Question 7

Which genetic disease has been linked to a mutation of the tumor-suppressor gene?

A) Hemochromatosis
B) Retinoblastoma
C) Familial breast cancer
D) Hemophilia A

Question 8

What is the chromosomal variation that causes Klinefelter syndrome?

A) Nondisjunction of the X chromosome in the father
B) Translocation of the X chromosome in the mother
C) Nondisjunction of X chromosome in the mother
D) Translocation of the Y chromosome in the father

Question 9

When a child inherits a disease that is autosomal recessive,it is inherited from:

A) Father
B) Mother
C) Both parents
D) Grandparent

Question 10

An amniocentesis is recommended for pregnant women who:

A) Have a history of chronic illness
B) Have a family history of genetic disorders
C) Have experienced in vitro fertilization
D) Had a late menarche

Question 11

A person with 47,XXY karyotype has the genetic disorder resulting in which syndrome?

A) Turner
B) Klinefelter
C) Down
D) Fragile X

Question 12

Inserting bone marrow cells into an individual who produces abnormal erythrocytes is an example of what type of therapy?

A) Somatic cell
B) Germ cell
C) Genetic engineering
D) Recombinant DNA

Question 13

What is the second most commonly recognized genetic cause of mental retardation?

A) Down syndrome
B) Fragile X syndrome
C) Klinefelter syndrome
D) Turner syndrome

Question 14

The purpose of a staining technique of chromosomes such as Giemsa is to:

A) Permit the mitotic process to be followed and monitored for variations.
B) Allow for the numbering of chromosomes and the identification of variations.
C) Identify new somatic cells formed through mitosis and cytokinesis.
D) Distinguish the sex chromosomes from the homologous chromosomes.

Question 15

An amniocentesis indicates a neural tube defect when an increase in which protein is evident?

A) Chorionic
B) Alpha fetoprotein
C) Amniotic
D) Embryonic

Question 16

Cystic fibrosis is caused by what type of gene?

A) X-linked dominant
B) X-linked recessive
C) Autosomal dominant
D) Autosomal recessive

Question 17

Transcription is best defined as a process by which:

A) DNA polymerase binds to the promoter site on ribonucleic acid (RNA).
B) RNA directs the synthesis of polypeptides for protein synthesis.
C) RNA is synthesized from a DNA template.
D) A base pair substitution results in a mutation of the amino acid sequence.

Question 18

A couple has two children diagnosed with an autosomal dominant genetic disease.What is the probability that the next child will have the same genetic disease?

A) One sixth
B) One fourth
C) One third
D) One half

Question 19

DNA replication requires the enzyme DNA polymerase to:

A) Travel along the single DNA strand, adding the correct nucleotide to the new strand
B) Move along the double strand of DNA to unwind the nucleotides of the double helix
C) Hold the double strand apart while the correct nucleotides are added to the strand
D) Transport the double strand of DNA from the nucleus to the cytoplasm for protein formation

Question 20

People diagnosed with neurofibromatosis have varying degrees of the condition because of the genetic principle of:

A) Penetrance
B) Expressivity
C) Dominance
D) Recessiveness

Question 21

Which disorders have similar modes of inheritance? (Select all that apply.)

A) Cri du chat syndrome
B) Duchenne muscular dystrophy
C) Polycystic kidney disease
D) Down syndrome
E) Becker muscular dystrophy

Question 22

DNA formation occurs in which of the cell's structures?

A) Nucleus
B) Cytoplasm
C) Organelle
D) Membrane

Question 23

Chromosomal abnormalities are the leading known cause of: (Select all that apply.)

A) Mental illness
B) Mental retardation
C) Fetal miscarriage
D) Cardiovascular disease
E) Respiratory disorders

Question 24

The advantage derived from human genome sequencing on genetic disorders focuses on: (Select all that apply.)

A) Identification of the mutated gene
B) Reversal of the mutation
C) Diagnosis of the existing disorder
D) Appropriate treatment
E) Prevention of the disorder

Question 25

Males are more often affected by which type of genetic disease?

A) Sex-linked dominant
B) Sex-influenced
C) Sex-linked
D) Sex-linked recessive

Question 26

A child with which genetic disorder has a characteristic cry?

A) Down syndrome
B) Klinefelter syndrome
C) Turner syndrome
D) Cri du chat

Question 27

Match the genetic terms with the corresponding diseases.Terms may be used more than once.
Cystic fibrosis

A)Autosomal dominant
B)Autosomal recessive
C)X-linked dominant
D)X-linked recessive

Question 28

Which is an important criterion for discerning autosomal recessive inheritance?

A) Consanguinity is sometimes present.
B) Females are affected more than males.
C) The disease is observed in both the parents, as well as in the siblings.
D) On average, one half of the offspring of the carrier will be affected.

Question 29

Males,having only one X chromosome (as is expected),are said to be:

A) Homozygous
B) Heterozygous
C) Hemizygous
D) Ambizygous

Question 30

The key to accurate DNA replication depends on which complementary base pairs? (Select all that apply.)

A) Adenine with thymine
B) Adenine with guanine
C) Guanine with cytosine
D) Cytosine with thymine
E) Guanine with thymine

Question 31

Match the genetic terms with the corresponding diseases.Terms may be used more than once.
Sickle cell disease

A)Autosomal dominant
B)Autosomal recessive
C)X-linked dominant
D)X-linked recessive

Question 32

Which statement is true regarding X-linked recessive conditions?

A) Such diseases use males as phenotypical carriers.
B) These conditions are passed from affected father to all of his female children.
C) 25% of an affected individual's grandsons will be affected.
D) Cystic fibrosis is an example of such a condition.

Question 33

Consanguinity refers to the mating of persons:

A) Who are unrelated
B) When one has an autosomal dominant disorder
C) Having common family relations
D) When one has a chromosomal abnormality

Question 34

What is the risk for the recurrence of autosomal dominant diseases?

A) 10%
B) 30%
C) 50%
D) 70%

Question 35

Match the genetic terms with the corresponding diseases.Terms may be used more than once.
Huntington disease

A)Autosomal dominant
B)Autosomal recessive
C)X-linked dominant
D)X-linked recessive

Question 36

The presence of a zygote having one chromosome with the normal complement of genes and one with a missing gene is characteristic of which genetic disorder?

A) Cri du chat
B) Down syndrome
C) Klinefelter syndrome
D) Turner syndrome

Question 37

Match the genetic terms with the corresponding diseases.Terms may be used more than once.
Duchenne muscular dystrophy

A)Autosomal dominant
B)Autosomal recessive
C)X-linked dominant
D)X-linked recessive

Question 38

An X-linked recessive disease can skip generations because:

A) Females are hemizygous for the X chromosome.
B) The disease can be transmitted through female carriers.
C) Mothers cannot pass X-linked genes to their sons.
D) These diseases need only one copy of the gene in females.

Question 39

Examples of prenatal diagnostic studies include: (Select all that apply.)

A) Chorionic villus sampling (CVS)
B) Amniocentesis
C) Carrier screening
D) Preimplantation genetic diagnosis (PGD)
E) Drug-sensitivity testing

Question 40

An individual's genetic makeup is referred to as his or her:

A) Phenotype
B) Genotype
C) Heterozygous locus
D) Homozygous locus