Actual Questions and Answers
Expert-Verified Explanation
This Exam contains:
✪ 50 Questions and Answers
✪ Multiple-choice and True/False Format
✪ Expert-Verified Explanations
✪ Verified with Trusted Textbooks
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
Answer: C
EXPLANATION: A karyotype is a photograph of chromosomes arranged by size, shape, and
number for analysis.
2. An error in which homologous chromosomes fail to separate during meiosis is
termed:
A) aneuploidy
B) nondisjunction
C) polyploidy
D) anaplasia
Answer: B
EXPLANATION: Nondisjunction results in gametes with abnormal numbers of chromosomes,
leading to chromosomal disorders.
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
Answer: A
, EXPLANATION: Aneuploid cells have a chromosome number that is not an exact multiple of
23, leading to genetic abnormalities.
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
Answer: C
EXPLANATION: Tetraploidy means the fetus has four complete sets of chromosomes (92
total), which is incompatible with life.
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
Answer: B
EXPLANATION: A mosaic has two or more cell lines with different karyotypes, potentially
resulting in milder disease expression.
6. The most common cause of Down syndrome is:
A) paternal nondisjunction
B) maternal translocations
C) maternal nondisjunction
D) paternal translocations
Answer: C
EXPLANATION: Maternal nondisjunction during meiosis is responsible for most cases of
trisomy 21 (Down syndrome).
7. Risk factors for Down syndrome include: