Deck 2: Genes and Genetic Diseases

Question 1

Which of the following mutations have the most significant effect on protein synthesis?

A) Base pair substitutions
B) Silent mutations
C) Intron mutations
D) Frameshift mutations

Answer 1

Frameshift mutations

Question 2

A 13-year-old girl has a karyotype that reveals an absent homologous X chromosome with only a single X chromosome present. Her condition is called:

A) Down syndrome.
B) Cri du chat syndrome.
C) Turner syndrome.
D) Edward syndrome.

Answer 2

Turner syndrome.

Question 3

Which of the following genetic disorders results in severe mental retardation caused by a deletion of part of chromosome 5?

A) Prader-Willi syndrome
B) Down syndrome
C) Cri du chat syndrome
D) Trisomy 5

Answer 3

Cri du chat syndrome

Question 4

Cystic fibrosis is caused by an _____ gene.

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

Question 5

If a person is a chromosomal mosaic, the person may:

A) be a carrier of the genetic disease.
B) have a mild form of the genetic disease.
C) have two genetic diseases.
D) be sterile as a result of the genetic disease.

Question 6

People who have neurofibromatosis will show varying degrees of the disease; this is because of the genetic principle of:

A) penetrance.
B) expressivity.
C) dominance.
D) recessiveness.

Question 7

A 20-year-old pregnant female gives birth to a stillborn child. Autopsy reveals that the fetus has 92 chromosomes. Which of the following describes this condition?

A) Euploidy
B) Triploidy
C) Tetraploidy
D) Aneuploidy

Question 8

The condition in which an extra portion of a chromosome is present in each cell is called:

A) fragmented trisomy.
B) partial trisomy.
C) translocated trisomy.
D) Down syndrome.

Question 9

A couple has three offspring: one child with an autosomal dominant disease trait and two who are normal. The father is affected by the autosomal dominant disease, but the mother does not have the disease gene. What is the recurrence risk of this autosomal dominant disease for their next child?

A) 50%
B) 33%
C) 25%
D) Impossible to determine

Question 10

The basic components of DNA are:

A) pentose sugars and four phosphate bases.
B) a phosphate molecule, deoxyribose, and four nitrogenous bases.
C) adenine, guanine, purine.
D) codons, oxygen, cytosine.

Question 11

A 15-year-old female is diagnosed with Prader-Willi syndrome. This condition is an example of:

A) gene imprinting.
B) an autosomal recessive trait.
C) an autosomal dominant trait.
D) a sex-linked trait.

Question 12

The base components of DNA are:

A) A, G, C, and U.
B) U, G, C, and T.
C) A, G, C, and T.
D) X, XX, XY, and YY.

Question 13

A DNA strand has a region with the sequence ATCGGATC. Which of the following would be a complementary strand?

A) CGATACGT
B) TAGCCTAG
C) TUGCCTUG
D) UAGCCUAG

Question 14

The most common cause of Down syndrome is:

A) paternal nondisjunction.
B) maternal translocations.
C) maternal nondisjunction.
D) paternal translocations.

Question 15

Risk factors for Down syndrome include:

A) fetal exposure to mutagens in the uterus.
B) increased paternal age.
C) family history of Down syndrome.
D) pregnancy in women over age 35.

Question 16

An error in which homologous chromosomes fail to separate during meiosis is termed:

A) aneuploidy.
B) nondisjunction.
C) polyploidy.
D) anaplasia.

Question 17

An ordered photographic display of a set of chromosomes from a single cell is a(n):

A) metaphase spread.
B) autosomal spread.
C) karyotype.
D) anaphase spread.

Question 18

A somatic cell that does not contain a multiple of 23 chromosomes is called:

A) a diploid cell.
B) a euploid cell.
C) a polyploidy cell.
D) a haploid cell.

Question 19

The process by which RNA directs the synthesis of protein is called:

A) termination.
B) transcription.
C) promotion.
D) translation.

Question 20

An XXY person has the genetic disorder called:

A) Turner syndrome.
B) Klinefelter syndrome.
C) Down syndrome.
D) fragile X syndrome.

Question 21

A 12-year-old male is diagnosed with Klinefelter syndrome. His karyotype would reveal which of the following?

A) XY
B) XX
C) XYY
D) XXY

Question 22

What is the diagnosis of a 13-year-old female who has a karyotype that reveals an absent homologous X chromosome with only a single X chromosome present? Her features include a short stature, widely spaced nipples, reduced carrying angle at the elbow, and sparse body hair.

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

Question 23

The gradual increase in height among the human population over the past 100 years is an example of:

A) polygenic trait.
B) multifactorial trait.
C) crossing over.
D) recombination.

Question 24

To express a polygenic trait:

A) genes must interact with the environment.
B) several genes must act together.
C) multiple mutations must occur in the same family.
D) in situ cloning must occur.

Question 25

A child is diagnosed with cystic fibrosis. History reveals that the child's parents are siblings. Cystic fibrosis was most likely the result of:

A) X inactivation.
B) genomic imprinting.
C) consanguinity.
D) obligate carriers.

Question 26

Joey, age 9, is admitted to a pediatric unit with Duchenne muscular dystrophy. He inherited this condition through a:

A) sex-linked dominant trait.
B) sex-influenced trait.
C) sex-limited trait.
D) sex-linked recessive trait.

Question 27

When considering how nitrogenous bases pair to form a double helix, which of the following pairs occur most often?

A) Cytosine-Guanine
B) Thymine-Cytosine
C) Adenine-Cytosine
D) Guanine-Thymine

Question 28

The person that a pedigree chart begins with is called the:

A) proband.
B) proposita.
C) propositus.
D) carrier.

Question 29

The regions of the heterogeneous nuclear RNA that must be spliced out to form functional RNA are called:

A) promotor sites.
B) introns.
C) exons.
D) anticodon.

Question 30

A child is born with blue eyes (bb). The child's mother has blue eyes and the father has brown eyes. Which of the following represents the father?

A) bb
B) Bb
C) BB
D) Bbb

Question 31

A 50-year-old male was recently diagnosed with Huntington disease. Transmission of this disease is associated with:

A) penetrance.
B) recurrence risk.
C) expressivity.
D) delayed age of onset.

Question 32

A normal male and a female carrier for red-green color blindness mate. Given that red-green color blindness is an X-linked recessive trait, what is the likelihood of their children being affected?

A) 25%
B) 50%
C) All females, no males
D) All males, no females

Question 33

The protein most important for DNA replication is:

A) RNA polymerase.
B) transfer RNA.
C) messenger RNA.
D) DNA polymerase.

Question 34

A 5-year-old male presents with mental retardation and is diagnosed with Fragile X syndrome. Which of the following is most likely to cause this syndrome?

A) Translocation
B) Inversion
C) Nondisjunction
D) Duplication at fragile sites