1
NORMAL STRUCTURE & FUNCTION / MOLECULAR GENETIC PRINCIPLES (Q1–12)
1. In DNA, cytosine pairs with guanine via how many hydrogen bonds?
A. One
B. Two
C. Three
D. Four
Answer: C — C-G pairing involves three hydrogen bonds, contributing to DNA stability .
2. Which enzyme is responsible for synthesizing the new DNA strand during replication?
A. Ligase
B. Helicase
C. DNA polymerase
D. Topoisomerase
Answer: C — DNA polymerase catalyzes nucleotide addition complementary to the template
strand .
3. A mutation that introduces a premature stop codon is classified as:
A. Missense
B. Nonsense
C. Frameshift
D. Silent
Answer: B — Nonsense mutations create premature termination codons .
4. Which inheritance pattern is characterized by male-to-male transmission?
A. X-linked recessive
B. Autosomal dominant
C. Autosomal recessive
D. Mitochondrial
Answer: B — Autosomal dominant traits can pass from father to son .
5. The CAG repeat expansion in the HTT gene is associated with:
A. Fragile X syndrome
B. Huntington disease
C. Myotonic dystrophy
D. Friedreich ataxia
Answer: B — Huntington disease results from CAG expansion in HTT .
6. Which DNA repair pathway corrects double-strand breaks using a homologous
template?
A. Non-homologous end joining
B. Base excision repair
C. Homologous recombination
, 2
D. Mismatch repair
Answer: C — Homologous recombination uses a sister chromatid for accurate repair .
7. Microsatellites are most useful for which application?
A. Detecting point mutations
B. Linkage analysis and loss of heterozygosity
C. Measuring protein expression
D. Identifying methylation patterns
Answer: B — Short tandem repeats are highly polymorphic and inherited, ideal for linkage
studies and LOH assessment .
8. The founder effect in population genetics refers to:
A. Random mating leading to equilibrium
B. A small group carrying only a subset of genetic variation
C. Gene flow increasing heterozygosity
D. Natural selection favoring advantageous alleles
Answer: B — The founder effect occurs when a new population is established by few
individuals .
9. Which epigenetic modification is most commonly associated with gene silencing?
A. Histone acetylation
B. DNA methylation at CpG islands
C. Histone phosphorylation
D. Chromatin remodeling
Answer: B — CpG island methylation typically leads to transcriptional silencing .
10. Heteroplasmy refers to:
A. Inheritance of two different alleles
B. Presence of both normal and mutated mitochondrial DNA
C. Loss of one chromosome
D. Gain of an extra chromosome
Answer: B — Heteroplasmy is the coexistence of normal and mutant mitochondrial genomes
.
11. Which population genetics equation is used to calculate allele frequencies at
equilibrium?
A. Hardy-Weinberg equation
B. Fisher's exact test
C. Poisson distribution
D. Kaplan-Meier estimator
Answer: A — Hardy-Weinberg equilibrium describes allele frequency stability .
12. Imprinting disorders such as Angelman and Prader-Willi syndromes result from:
A. Trinucleotide repeat expansions
, 3
B. Abnormal parent-of-origin gene expression
C. Mitochondrial mutations
D. Chromosomal translocations
Answer: B — Imprinting disorders arise from disrupted parent-of-origin specific gene
expression .
TECHNIQUES & METHODS (Q13–30)
13. Which technique allows quantification of gene expression at the mRNA level?
A. Southern blot
B. Real-time quantitative PCR (qPCR)
C. Western blot
D. FISH
Answer: B — qPCR quantifies specific RNA transcripts after reverse transcription to cDNA .
14. Which sequencing method is considered the gold standard for detecting single
nucleotide variants?
A. Whole-exome sequencing
B. RNA-seq
C. Sanger sequencing
D. Microarray
Answer: C — Sanger sequencing is highly accurate for single nucleotide changes .
15. Which technique detects fusion transcripts at the RNA level?
A. Southern blot
B. RT-PCR
C. Western blot
D. SNP array
Answer: B — RT-PCR amplifies RNA-derived cDNA for fusion transcript detection .
16. In next-generation sequencing, what is the purpose of adapter ligation?
A. Amplify DNA
B. Allow DNA fragments to bind to the sequencing flow cell
C. Cut DNA at specific sites
D. Reverse transcribe RNA
Answer: B — Adapters enable DNA fragments to attach to the flow cell .
17. Which method is most appropriate for detecting a single base substitution at a known
site?
A. Southern blot
B. Allele-specific PCR
C. Western blot
NORMAL STRUCTURE & FUNCTION / MOLECULAR GENETIC PRINCIPLES (Q1–12)
1. In DNA, cytosine pairs with guanine via how many hydrogen bonds?
A. One
B. Two
C. Three
D. Four
Answer: C — C-G pairing involves three hydrogen bonds, contributing to DNA stability .
2. Which enzyme is responsible for synthesizing the new DNA strand during replication?
A. Ligase
B. Helicase
C. DNA polymerase
D. Topoisomerase
Answer: C — DNA polymerase catalyzes nucleotide addition complementary to the template
strand .
3. A mutation that introduces a premature stop codon is classified as:
A. Missense
B. Nonsense
C. Frameshift
D. Silent
Answer: B — Nonsense mutations create premature termination codons .
4. Which inheritance pattern is characterized by male-to-male transmission?
A. X-linked recessive
B. Autosomal dominant
C. Autosomal recessive
D. Mitochondrial
Answer: B — Autosomal dominant traits can pass from father to son .
5. The CAG repeat expansion in the HTT gene is associated with:
A. Fragile X syndrome
B. Huntington disease
C. Myotonic dystrophy
D. Friedreich ataxia
Answer: B — Huntington disease results from CAG expansion in HTT .
6. Which DNA repair pathway corrects double-strand breaks using a homologous
template?
A. Non-homologous end joining
B. Base excision repair
C. Homologous recombination
, 2
D. Mismatch repair
Answer: C — Homologous recombination uses a sister chromatid for accurate repair .
7. Microsatellites are most useful for which application?
A. Detecting point mutations
B. Linkage analysis and loss of heterozygosity
C. Measuring protein expression
D. Identifying methylation patterns
Answer: B — Short tandem repeats are highly polymorphic and inherited, ideal for linkage
studies and LOH assessment .
8. The founder effect in population genetics refers to:
A. Random mating leading to equilibrium
B. A small group carrying only a subset of genetic variation
C. Gene flow increasing heterozygosity
D. Natural selection favoring advantageous alleles
Answer: B — The founder effect occurs when a new population is established by few
individuals .
9. Which epigenetic modification is most commonly associated with gene silencing?
A. Histone acetylation
B. DNA methylation at CpG islands
C. Histone phosphorylation
D. Chromatin remodeling
Answer: B — CpG island methylation typically leads to transcriptional silencing .
10. Heteroplasmy refers to:
A. Inheritance of two different alleles
B. Presence of both normal and mutated mitochondrial DNA
C. Loss of one chromosome
D. Gain of an extra chromosome
Answer: B — Heteroplasmy is the coexistence of normal and mutant mitochondrial genomes
.
11. Which population genetics equation is used to calculate allele frequencies at
equilibrium?
A. Hardy-Weinberg equation
B. Fisher's exact test
C. Poisson distribution
D. Kaplan-Meier estimator
Answer: A — Hardy-Weinberg equilibrium describes allele frequency stability .
12. Imprinting disorders such as Angelman and Prader-Willi syndromes result from:
A. Trinucleotide repeat expansions
, 3
B. Abnormal parent-of-origin gene expression
C. Mitochondrial mutations
D. Chromosomal translocations
Answer: B — Imprinting disorders arise from disrupted parent-of-origin specific gene
expression .
TECHNIQUES & METHODS (Q13–30)
13. Which technique allows quantification of gene expression at the mRNA level?
A. Southern blot
B. Real-time quantitative PCR (qPCR)
C. Western blot
D. FISH
Answer: B — qPCR quantifies specific RNA transcripts after reverse transcription to cDNA .
14. Which sequencing method is considered the gold standard for detecting single
nucleotide variants?
A. Whole-exome sequencing
B. RNA-seq
C. Sanger sequencing
D. Microarray
Answer: C — Sanger sequencing is highly accurate for single nucleotide changes .
15. Which technique detects fusion transcripts at the RNA level?
A. Southern blot
B. RT-PCR
C. Western blot
D. SNP array
Answer: B — RT-PCR amplifies RNA-derived cDNA for fusion transcript detection .
16. In next-generation sequencing, what is the purpose of adapter ligation?
A. Amplify DNA
B. Allow DNA fragments to bind to the sequencing flow cell
C. Cut DNA at specific sites
D. Reverse transcribe RNA
Answer: B — Adapters enable DNA fragments to attach to the flow cell .
17. Which method is most appropriate for detecting a single base substitution at a known
site?
A. Southern blot
B. Allele-specific PCR
C. Western blot
