QUESTIONS AND ANSWERS
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. - CORRECT ANSWER-c
An error in which homologous chromosomes fail to separate
during meiosis is termed:
A) aneuploidy.
B) nondisjunction.
C) polyploidy.
D) anaplasia. - CORRECT ANSWER-b
A somatic cell that does not contain a multiple of 23
chromosomes is called:
A) an aneuploid cell.
B) a euploid cell.
C) a polyploidy cell.
D) a haploid cell. - CORRECT ANSWER-a
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 - CORRECT ANSWER-c
,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. - CORRECT
ANSWER-b
The most common cause of Down syndrome is:
A) paternal nondisjunction.
B) maternal translocations.
C) maternal nondisjunction.
D) paternal translocations. - CORRECT ANSWER-c
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. - CORRECT ANSWER-d
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 - CORRECT ANSWER-c
A child is diagnosed with cystic fibrosis. History reveals that the
child's parents are first cousins. Cystic fibrosis was most likely
the result of:
A) X inactivation.
B) genomic imprinting.
C) consanguinity.
D) obligate carriers. - CORRECT ANSWER-c
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. - CORRECT ANSWER-d
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. - CORRECT ANSWER-d
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. - CORRECT ANSWER-b
Cystic fibrosis is caused by an _____ gene.
A) X-linked dominant
B) X-linked recessive
C) autosomal dominant
D) autosomal recessive - CORRECT ANSWER-d
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. - CORRECT ANSWER-b
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. - CORRECT ANSWER-b
, 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 - CORRECT ANSWER-a
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 - CORRECT ANSWER-d
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 - CORRECT ANSWER-d
The outward manifestation of a disease, often influenced by
both genes and the environment, is called the disease:
A) genotype.
B) allele.
C) phenotype.
D) dominance. - CORRECT ANSWER-c
Which of the following genetic diseases manifests with
progressive dementia in middle to later adulthood?
A) Duchenne muscular dystrophy
B) Cystic fibrosis