(2026) Q&A | Walden University
1. Which process describes the movement of genetic material between
homologous chromosomes during meiosis?
A) Crossover
B) Nondisjunction
C) Linkage
D) Mosaicism
Correct Answer: Crossover
Rationale: Crossover is the exchange of DNA segments between non‑sister
chromatids, increasing genetic diversity. Nondisjunction is the failure of
chromosomes to separate; linkage describes genes inherited together;
mosaicism is the presence of different cell lines.
2. A child is diagnosed with a syndrome caused by a deletion on the short arm of
chromosome 5. Which disorder is this?
A) Down syndrome
B) Cri du Chat syndrome
C) Turner syndrome
D) Klinefelter syndrome
Correct Answer: Cri du Chat syndrome
,Rationale: Cri du Chat results from a deletion on chromosome 5p. It presents
with a cat‑like cry in infancy, microcephaly, severe intellectual disability, and
cardiac defects. The other syndromes have different genetic causes.
3. A female adolescent presents with short stature, webbed neck, and widely
spaced nipples. A karyotype reveals 45 chromosomes with a single X. What is
the diagnosis?
A) Klinefelter syndrome
B) Fragile X syndrome
C) Turner syndrome
D) Down syndrome
Correct Answer: Turner syndrome
Rationale: Turner syndrome (45,X) is characterized by short stature, webbed
neck, shield chest, and ovarian dysgenesis. Klinefelter is 47,XXY; Fragile X is an
X‑linked dominant trinucleotide repeat; Down syndrome is trisomy 21.
4. An individual possesses two different cell lines, each with a distinct
karyotype. This condition is termed:
A) Chimera
B) Carrier
C) Proband
D) Chromosomal mosaic
Correct Answer: Chromosomal mosaic
, Rationale: Mosaicism arises from early mitotic nondisjunction, producing
multiple karyotypes in one person. A chimera results from fused zygotes; a
carrier has a recessive allele; a proband is the first affected family member.
5. Cystic fibrosis is inherited in which pattern?
A) Autosomal recessive
B) Autosomal dominant
C) X‑linked recessive
D) Mitochondrial
Correct Answer: Autosomal recessive
Rationale: CF requires two mutated CFTR alleles; both parents are carriers.
Autosomal dominant needs only one allele; X‑linked recessive primarily affects
males; mitochondrial inheritance is maternal.
6. An increase in the number of cells in a tissue is defined as:
A) Atrophy
B) Hyperplasia
C) Metaplasia
D) Hypertrophy
Correct Answer: Hyperplasia