🏥 USMLE Exam Prep

A common mechanism by which certain bacterial pathogens, such as Streptococcus pneumoniae and Haemophilus influenzae, evade phagocytosis and contribute to their virulence is the production of which structural component?

A Flagella
B Pili
C Capsule
D Endotoxin

✓ Correct Answer: Option C

Bacterial capsules are composed of polysaccharides and act as a protective layer that inhibits phagocytosis by host immune cells like macrophages and neutrophils, thereby enhancing bacterial survival and virulence.

💡 Why is C) the correct answer?

The correct answer to the question "A common mechanism by which certain bacterial pathogens, such as Streptococcus pneumoniae and Haemophilus influenzae, evade phagocytosis and contribute to their virulence is the production of which structural component?" is Option C: Capsule.

The other options — A) Flagella, B) Pili, D) Endotoxin — are incorrect for this USMLE Exam Prep question. As explained above: Bacterial capsules are composed of polysaccharides and act as a protective layer that inhibits phagocytosis by host immune cells like macrophages and neutrophils, thereby enhancing bacterial survival…

📚 About This USMLE Exam Prep Practice Question

This 1-level USMLE Exam Prep question from the Step 1 – Basic Sciences topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free USMLE Exam Prep practice test or use flashcards for spaced repetition review.

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