PLTW - Medical Interventions Final Exam Study Guide Questions and Answers | Latest Version | 2025/2026 | Correct & Verified

PLTW - Medical Interventions Final Exam Study Guide Questions and Answers | Latest Version | 2025/2026 | Correct & Verified What is the primary function of macrophages during an early infection? To engulf and destroy invading pathogens through phagocytosis. How does a viral infection typically enter a host cell? By binding to specific surface receptors and injecting or releasing its genetic material. What is the purpose of gram staining when identifying bacteria? To classify bacteria based on differences in their cell wall structure. What does a rising antibody level in a patient’s blood indicate? An active immune response to a current or recent infection. How do memory B cells help protect the body from future infections? They rapidly recognize and respond to pathogens previously encountered. 2 What role does inflammation play in infectious diseases? It isolates pathogens and recruits immune cells to the infection site. How do bacteria develop antibiotic resistance over time? Through genetic mutations or acquiring resistance genes from other bacteria. What does a PCR test detect in a suspected infectious disease case? Specific DNA sequences of the pathogen. How can hand hygiene reduce the spread of infectious diseases? By removing or killing pathogens before they transfer to others. What is the function of a vaccine in preventing illness? To stimulate the immune system to develop protective antibodies. How do T-helper cells assist in fighting infections? They activate B cells and cytotoxic T cells during an immune response. 3 What is the main purpose of quarantine during an outbreak? To prevent infected or exposed individuals from transmitting disease. How do antibiotics such as penicillin cause bacterial death? By disrupting the formation of cell walls. What does the term “vector” mean in infectious disease? An organism that transmits a pathogen from one host to another. Why are viruses not classified as living organisms? They cannot reproduce or carry out metabolism without a host cell. How does herd immunity help control infectious diseases? It reduces pathogen spread when a large portion of the population is immune. Why is it important to complete an entire antibiotic course? To ensure all bacteria are eliminated and reduce resistance risk. 4 How do antigens trigger an immune response? By being recognized as foreign by immune cells. What is the purpose of a lumbar puncture when diagnosing infections? To analyze cerebrospinal fluid for signs of pathogens. How do cytotoxic T cells destroy infected cells? By releasing enzymes that cause apoptosis in infected host cells. What makes prions different from other infectious agents? They are misfolded proteins that transmit disease without genetic material. How do bacterial toxins cause illness? By damaging tissues or altering normal cellular functions. What role does the skin play in preventing infections? It acts as a physical barrier to block pathogen entry. 5 How does an ELISA test detect infectious diseases? By identifying the presence of specific antibodies