Answers
1. 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
ANS c
2. An error in which homologous chromosomes fail to separate during
meiosis is termed:
A) aneuploidy.
B) nondisjunction.
C) polyploidy.
D) anaplasia
ANS b
3. 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
ANS a
4. 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:
ANS c
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
ANS b
6. The most common cause of Down syndrome is:
A) paternal nondisjunction.
B) maternal translocations.
,C) maternal nondisjunction.
D) paternal translocations
ANS c
7. 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
ANS d
8. 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:
ANS c
9. 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
ANS c
10. 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
ANS d
11. A 50-year-old male was recently diagnosed with Huntington
disease. Trans- mission of this disease is associated with:
A) penetrance.
B) recurrence risk.
C) expressivity.
D) delayed age of onset
ANS d