A thorough grasp of molecular biology is fundamental to understanding modern pharmaceutical science. For PharmD students, the core principles of DNA replication, gene transcription, and protein translation are not just academic concepts; they are the basis for the development of revolutionary biopharmaceuticals. This knowledge is crucial for comprehending the mechanisms behind mRNA vaccines, gene therapies, and recombinant protein drugs. This quiz will test your foundational knowledge of these essential molecular processes.
1. Which of the following nitrogenous bases is found in RNA but not in DNA?
- Adenine
- Guanine
- Cytosine
- Uracil
Answer: Uracil
2. The process of synthesizing an RNA molecule from a DNA template is known as:
- Replication
- Translation
- Transcription
- Post-translational modification
Answer: Transcription
3. In the DNA double helix, adenine pairs with which base?
- Guanine
- Cytosine
- Uracil
- Thymine
Answer: Thymine
4. What is the name of the enzyme that unwinds the DNA double helix during replication?
- DNA Polymerase
- DNA Ligase
- Helicase
- Primase
Answer: Helicase
5. The synthesis of a protein from an mRNA template occurs in which cellular organelle?
- Nucleus
- Mitochondrion
- Ribosome
- Endoplasmic Reticulum
Answer: Ribosome
6. A three-nucleotide sequence on an mRNA molecule that specifies a particular amino acid is called a(n):
- Codon
- Anticodon
- Exon
- Intron
Answer: Codon
7. The process by which non-coding regions are removed from pre-mRNA in eukaryotes is called:
- Capping
- Polyadenylation
- Splicing
- Replication
Answer: Splicing
8. DNA replication is described as “semi-conservative” because:
- Only one strand of the DNA is replicated
- Each new DNA molecule consists of one old strand and one new strand
- The process is highly error-prone
- It only occurs in half of the cell cycle
Answer: Each new DNA molecule consists of one old strand and one new strand
9. Which molecule is responsible for bringing the correct amino acid to the ribosome during translation?
- mRNA
- rRNA
- tRNA
- DNA
Answer: tRNA
10. What is the primary function of DNA polymerase?
- To synthesize mRNA during transcription
- To add nucleotides to a growing DNA strand during replication
- To unwind the DNA double helix
- To join fragments of DNA together
Answer: To add nucleotides to a growing DNA strand during replication
11. The short fragments of DNA synthesized on the lagging strand during replication are called:
- Okazaki fragments
- Splicing fragments
- Promoter sequences
- Start codons
Answer: Okazaki fragments
12. The addition of a 5′ cap and a 3′ poly-A tail to an mRNA molecule serves to:
- Mark it for immediate degradation
- Prevent it from leaving the nucleus
- Increase its stability and aid in translation initiation
- Convert it back into DNA
Answer: Increase its stability and aid in translation initiation
13. Which of the following serves as the “start codon” for protein synthesis?
- UGA
- UAA
- UAG
- AUG
Answer: AUG
14. The bond that forms between adjacent amino acids in a growing polypeptide chain is a(n):
- Peptide bond
- Hydrogen bond
- Ionic bond
- Glycosidic bond
Answer: Peptide bond
15. What are restriction enzymes commonly used for in molecular biology?
- To replicate DNA
- To translate proteins
- To cut DNA at specific recognition sequences
- To unwind RNA molecules
Answer: To cut DNA at specific recognition sequences
16. The process of producing multiple copies of a specific DNA segment is known as:
- Gel electrophoresis
- Polymerase Chain Reaction (PCR)
- Splicing
- Western blotting
Answer: Polymerase Chain Reaction (PCR)
17. A plasmid is a small, circular DNA molecule often used in recombinant DNA technology as a(n):
- Vector to carry foreign genes into a host cell
- Source of amino acids
- Enzyme to cut DNA
- Ribosome component
Answer: Vector to carry foreign genes into a host cell
18. What is the central dogma of molecular biology?
- RNA is transcribed into DNA, which is translated into protein.
- Protein is transcribed into RNA, which is translated into DNA.
- DNA is replicated, then translated directly into protein.
- DNA is transcribed into RNA, which is translated into protein.
Answer: DNA is transcribed into RNA, which is translated into protein.
19. Post-translational modifications, such as phosphorylation or glycosylation, occur after which process?
- Transcription
- Replication
- Splicing
- Translation
Answer: Translation
20. In gene transcription, the strand of DNA that is read to create the mRNA molecule is called the:
- Coding strand
- Lagging strand
- Template strand
- Leading strand
Answer: Template strand
21. The sequence of DNA that RNA polymerase binds to in order to initiate transcription is called the:
- Enhancer
- Terminator
- Promoter
- Exon
Answer: Promoter
22. Which type of RNA is a major structural and catalytic component of the ribosome?
- mRNA (messenger RNA)
- tRNA (transfer RNA)
- rRNA (ribosomal RNA)
- siRNA (small interfering RNA)
Answer: rRNA (ribosomal RNA)
23. The genetic code is said to be “degenerate” or “redundant.” What does this mean?
- The code is flawed and often makes mistakes
- Multiple codons can specify the same amino acid
- A single codon can code for multiple different amino acids
- The code is not universal across different species
Answer: Multiple codons can specify the same amino acid
24. The function of DNA ligase in DNA replication is to:
- Unwind the DNA helix
- Add new nucleotides to the growing chain
- Create an RNA primer
- Join the Okazaki fragments on the lagging strand
Answer: Join the Okazaki fragments on the lagging strand
25. A change in the DNA sequence of a gene is known as a(n):
- Translation
- Transcription
- Mutation
- In-situ hybridization
Answer: Mutation
26. Recombinant human insulin is produced using which molecular biology technique?
- Inserting the human insulin gene into a bacterial plasmid
- Extracting insulin directly from human donors
- Synthesizing insulin using organic chemistry
- Using viral vectors to produce insulin in plants
Answer: Inserting the human insulin gene into a bacterial plasmid
27. What is the purpose of the poly-A tail on an mRNA molecule?
- It initiates transcription
- It helps protect the mRNA from degradation and aids in its export from the nucleus
- It codes for the amino acid methionine
- It splices out the introns
Answer: It helps protect the mRNA from degradation and aids in its export from the nucleus
28. The anticodon is a three-nucleotide sequence found on which molecule?
- DNA
- mRNA
- tRNA
- Ribosome
Answer: tRNA
29. In eukaryotes, where does transcription take place?
- Cytoplasm
- Ribosome
- Nucleus
- Golgi apparatus
Answer: Nucleus
30. In eukaryotes, where does translation take place?
- Nucleus
- Cytoplasm
- Cell membrane
- Lysosome
Answer: Cytoplasm
31. The term “genome” refers to:
- All of the proteins in a cell
- All of the RNA in a cell
- The complete set of genetic material (DNA) in an organism
- A single gene responsible for a specific trait
Answer: The complete set of genetic material (DNA) in an organism
32. What is the function of a stop codon in protein synthesis?
- It codes for a special amino acid that stops the process
- It signals the ribosome to terminate translation
- It causes the mRNA to form a hairpin loop
- It initiates a new round of translation
Answer: It signals the ribosome to terminate translation
33. The technique of gene editing, which allows for precise modification of DNA sequences, is most famously associated with which system?
- PCR
- CRISPR-Cas9
- Western Blot
- Sanger Sequencing
Answer: CRISPR-Cas9
34. A key difference between DNA polymerase and RNA polymerase is that:
- DNA polymerase synthesizes RNA, and RNA polymerase synthesizes DNA
- DNA polymerase requires a primer to initiate synthesis, while RNA polymerase does not
- Only RNA polymerase can proofread its work
- DNA polymerase works in the cytoplasm, while RNA polymerase works in the nucleus
Answer: DNA polymerase requires a primer to initiate synthesis, while RNA polymerase does not
35. An “exon” is a segment of a gene that:
- Is removed during mRNA splicing
- Is part of the final, mature mRNA transcript
- Signals the start of transcription
- Is a non-coding region of DNA
Answer: Is part of the final, mature mRNA transcript
36. A viral vector in gene therapy is used to:
- Deliver a therapeutic gene into target cells
- Cause a viral infection to boost the immune system
- Analyze the protein content of a cell
- Cut the patient’s DNA into small fragments
Answer: Deliver a therapeutic gene into target cells
37. How do mRNA vaccines (like some COVID-19 vaccines) work?
- They inject a weakened form of the virus into the body
- They provide host cells with mRNA that codes for a viral antigen, prompting an immune response
- They use a harmless virus to deliver DNA into the cells
- They are made of purified viral proteins
Answer: They provide host cells with mRNA that codes for a viral antigen, prompting an immune response
38. The process of a cell taking up foreign DNA from its environment is called:
- Transformation
- Conjugation
- Transduction
- Mutation
Answer: Transformation
39. What type of chemical bond connects the two strands of a DNA molecule?
- Covalent bonds
- Ionic bonds
- Peptide bonds
- Hydrogen bonds
Answer: Hydrogen bonds
40. The backbone of a DNA or RNA strand is composed of alternating:
- Sugar and base units
- Phosphate and base units
- Sugar and phosphate units
- Amino acid and phosphate units
Answer: Sugar and phosphate units
41. “RNA interference” (RNAi) is a biological process in which RNA molecules:
- Promote the translation of a specific mRNA
- Inhibit gene expression or translation by neutralizing targeted mRNA molecules
- Repair mutations in DNA
- Act as a template for DNA synthesis
Answer: Inhibit gene expression or translation by neutralizing targeted mRNA molecules
42. The creation of a “transgenic animal” involves:
- Cloning an existing animal
- Introducing foreign DNA into an animal’s genome
- Cross-breeding two different species
- Mutating an animal using radiation
Answer: Introducing foreign DNA into an animal’s genome
43. A reading frame in translation is defined by the:
- Promoter sequence
- Start codon
- Poly-A tail
- 5′ cap
Answer: Start codon
44. What would be the consequence of a mutation that changes a codon for an amino acid into a stop codon?
- The resulting protein would be longer than normal
- The resulting protein would be shorter than normal (truncated)
- There would be no effect on the protein
- The protein would have a single incorrect amino acid
Answer: The resulting protein would be shorter than normal (truncated)
45. Monoclonal antibodies are biopharmaceuticals that are produced from:
- A population of identical immune cells (clones)
- A mixture of different immune cells
- Bacterial cultures
- Plant extracts
Answer: A population of identical immune cells (clones)
46. Which structural feature gives DNA its characteristic “double helix” shape?
- The covalent bonds in the sugar-phosphate backbone
- The base pairing of A with T and G with C
- The interaction of the DNA with histone proteins
- The presence of deoxyribose sugar
Answer: The base pairing of A with T and G with C
47. A “silent” mutation is one that:
- Occurs in a non-coding region of DNA
- Changes a codon but does not change the specified amino acid
- Results in a non-functional protein
- Always leads to a visible change in the organism’s phenotype
Answer: Changes a codon but does not change the specified amino acid
48. What is the role of primase in DNA replication?
- It synthesizes a short RNA primer to provide a starting point for DNA polymerase
- It unwinds the DNA helix
- It joins DNA fragments together
- It removes the RNA primers after replication
Answer: It synthesizes a short RNA primer to provide a starting point for DNA polymerase
49. The field of pharmacogenomics studies how:
- Genes affect a person’s response to drugs
- Drugs can be used to alter a person’s genes
- All drugs are metabolized in the same way
- Diet and lifestyle affect the human genome
Answer: Genes affect a person’s response to drugs
50. Understanding the molecular biology of a disease allows for the development of:
- A single drug that works for all patients
- Targeted therapies that act on specific molecules involved in the disease process
- Only surgical treatment options
- Only herbal remedies
Answer: Targeted therapies that act on specific molecules involved in the disease process
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
Mail- Sachin@pharmacyfreak.com