Page 1 of 69
PLTW Medical Interventions Final Exam ACTUAL EXAM
2026-2027 COMPLETE 250 QUESTIONS AND VERIFIED
SOLUTIONS LATEST UPDATE THIS YEAR
PLTW Medical Interventions – actual Multiple-Choice Questions (With Rationales)
1. A patient’s blood sample shows a very high concentration of disease antigens. What does
this most likely suggest?
A. The patient is immune
B. The patient was infected recently
C. The patient may be close to the source of infection
D. The patient has recovered
Correct Answer: C
Rationale: High antigen concentration suggests early exposure and proximity to the outbreak
source (patient zero).
2. Which tool would best help scientists compare an unknown pathogen’s DNA to known
organisms?
A. ELISA
B. BLAST
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C. Audiogram
D. Disc diffusion
Correct Answer: B
Rationale: BLAST is a bioinformatics tool used to compare DNA sequences.
3. Which bacterial structure allows attachment to human cells?
A. Ribosome
B. Nucleoid
C. Adhesins
D. Plasmid
Correct Answer: C
Rationale: Adhesins help bacteria attach to surfaces and host cells.
4. A lab technician notices pink-stained bacteria after Gram staining. What is most likely true?
A. Thick cell wall
B. Thin cell wall
C. No cell wall
D. Resistant to all antibiotics
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Correct Answer: B
Rationale: Gram-negative bacteria stain pink and have thin cell walls.
5. Which process allows bacteria to exchange DNA through direct contact?
A. Transduction
B. Transformation
C. Conjugation
D. Mutation
Correct Answer: C
Rationale: Conjugation requires physical contact between bacteria.
6. Which step in ELISA produces the visible color change?
A. Antigen binding
B. Primary antibody binding
C. Secondary antibody binding
D. Enzyme–substrate reaction
Correct Answer: D
Rationale: The enzyme reacts with the substrate to create color.
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7. Why are fluoroquinolones effective against many Gram-negative bacteria?
A. They destroy cell walls
B. They block folic acid
C. They inhibit DNA replication
D. They prevent attachment
Correct Answer: C
Rationale: Fluoroquinolones inhibit DNA gyrase, stopping replication.
8. Which action most contributes to antibiotic resistance?
A. Exercising regularly
B. Skipping doses of antibiotics
C. Washing hands
D. Getting vaccinated
Correct Answer: B
Rationale: Incomplete treatment allows resistant bacteria to survive.
9. Which type of hearing loss involves damage to auditory nerves?
PLTW Medical Interventions Final Exam ACTUAL EXAM
2026-2027 COMPLETE 250 QUESTIONS AND VERIFIED
SOLUTIONS LATEST UPDATE THIS YEAR
PLTW Medical Interventions – actual Multiple-Choice Questions (With Rationales)
1. A patient’s blood sample shows a very high concentration of disease antigens. What does
this most likely suggest?
A. The patient is immune
B. The patient was infected recently
C. The patient may be close to the source of infection
D. The patient has recovered
Correct Answer: C
Rationale: High antigen concentration suggests early exposure and proximity to the outbreak
source (patient zero).
2. Which tool would best help scientists compare an unknown pathogen’s DNA to known
organisms?
A. ELISA
B. BLAST
,Page 2 of 69
C. Audiogram
D. Disc diffusion
Correct Answer: B
Rationale: BLAST is a bioinformatics tool used to compare DNA sequences.
3. Which bacterial structure allows attachment to human cells?
A. Ribosome
B. Nucleoid
C. Adhesins
D. Plasmid
Correct Answer: C
Rationale: Adhesins help bacteria attach to surfaces and host cells.
4. A lab technician notices pink-stained bacteria after Gram staining. What is most likely true?
A. Thick cell wall
B. Thin cell wall
C. No cell wall
D. Resistant to all antibiotics
,Page 3 of 69
Correct Answer: B
Rationale: Gram-negative bacteria stain pink and have thin cell walls.
5. Which process allows bacteria to exchange DNA through direct contact?
A. Transduction
B. Transformation
C. Conjugation
D. Mutation
Correct Answer: C
Rationale: Conjugation requires physical contact between bacteria.
6. Which step in ELISA produces the visible color change?
A. Antigen binding
B. Primary antibody binding
C. Secondary antibody binding
D. Enzyme–substrate reaction
Correct Answer: D
Rationale: The enzyme reacts with the substrate to create color.
, Page 4 of 69
7. Why are fluoroquinolones effective against many Gram-negative bacteria?
A. They destroy cell walls
B. They block folic acid
C. They inhibit DNA replication
D. They prevent attachment
Correct Answer: C
Rationale: Fluoroquinolones inhibit DNA gyrase, stopping replication.
8. Which action most contributes to antibiotic resistance?
A. Exercising regularly
B. Skipping doses of antibiotics
C. Washing hands
D. Getting vaccinated
Correct Answer: B
Rationale: Incomplete treatment allows resistant bacteria to survive.
9. Which type of hearing loss involves damage to auditory nerves?
