Wilkes University | Q & A | 2026/2027 Edition
(PDF)
1. Which term describes the organized arrangement of chromosomes used for genetic analysis?
A) Chromatid
B) Centromere
C) Karyotype
D) Nucleosome
Correct Answer: Karyotype
Rationale: A karyotype is the organized visual representation of all chromosomes in a cell, arranged in
homologous pairs according to size and banding pattern. It is used clinically to detect chromosomal
abnormalities such as trisomies, deletions, or translocations. This technique is essential for diagnosing
genetic disorders.
2. Failure of homologous chromosomes to separate during meiosis is termed:
A) Aneuploidy
B) Nondisjunction
C) Polyploidy
D) Anaplasia
Correct Answer: Nondisjunction
Rationale: Nondisjunction is the failure of homologous chromosomes to separate during meiosis,
resulting in gametes with abnormal chromosome numbers. This can lead to conditions such as Down
syndrome (trisomy 21), Turner syndrome (45,XO), or Klinefelter syndrome (47,XXY) when fertilization
occurs.
3. Which genetic disorder follows an autosomal dominant inheritance pattern?
,A) Cystic fibrosis
B) Huntington's disease
C) Sickle cell disease
D) Hemophilia A
Correct Answer: Huntington's disease
Rationale: Huntington's disease follows an autosomal dominant inheritance pattern, meaning only one
copy of the mutated gene is needed for disease expression. Each child of an affected parent has a 50%
risk of inheriting the disorder. Cystic fibrosis and sickle cell disease are autosomal recessive, while
hemophilia A is X-linked.
4. Which genetic disorder follows an autosomal recessive inheritance pattern?
A) Huntington's disease
B) Cystic fibrosis
C) Neurofibromatosis
D) Marfan syndrome
Correct Answer: Cystic fibrosis
Rationale: Cystic fibrosis follows an autosomal recessive inheritance pattern, requiring two copies of the
mutated CFTR gene for disease expression. Both parents must be carriers for a child to be affected.
Huntington's disease, neurofibromatosis, and Marfan syndrome are autosomal dominant disorders.
5. Which chromosomal abnormality is characterized by trisomy 21?
A) Turner syndrome
B) Klinefelter syndrome
C) Down syndrome
D) Edwards syndrome
, Correct Answer: Down syndrome
Rationale: Down syndrome is characterized by trisomy 21, meaning three copies of chromosome 21.
Turner syndrome (45,XO) involves monosomy of the X chromosome, Klinefelter syndrome (47,XXY)
involves an extra X chromosome, and Edwards syndrome involves trisomy 18.
6. Which of the following is an X-linked recessive disorder?
A) Huntington's disease
B) Cystic fibrosis
C) Hemophilia A
D) Achondroplasia
Correct Answer: Hemophilia A
Rationale: Hemophilia A is an X-linked recessive disorder caused by deficiency of clotting factor VIII. It
primarily affects males, who have only one X chromosome. Female carriers typically have milder
symptoms due to X-inactivation. This inheritance pattern explains why the disorder is more common in
males.
7. What is the fundamental genetic alteration that characterizes neoplasia?
A) Loss of all chromosomal material
B) Genetic mutations that confer a growth advantage
C) Decreased expression of all genes
D) Increased apoptosis of normal cells
Correct Answer: Genetic mutations that confer a growth advantage
Rationale: Neoplasia results from the accumulation of genetic mutations that confer a growth advantage
to cells. These mutations affect proto-oncogenes (which become oncogenes), tumor suppressor genes
(which are inactivated), and genes involved in DNA repair, leading to uncontrolled cellular proliferation.