microbiology chapter 11 test bank

Correct Answer: A

Rationale: The correct answer is A: incidence. Incidence refers to the number of new cases of a disease occurring within a specific time period in relation to the healthy population. It helps in understanding the risk of developing the disease. Prevalence (B) is the total number of existing cases at a given point in time. Virulence (C) is the severity of the disease once contracted. Mortality (D) refers to the number of deaths due to the disease, not the new cases. Therefore, the correct term for new cases is incidence.

Correct Answer: A

Rationale: The correct answer is A: Β-lactamase. In ELISA, enzymes like alkaline phosphatase, horseradish peroxidase, and Β-galactosidase are commonly used as labels to detect the presence of specific molecules. Β-lactamase is not typically used in ELISA as it is an enzyme used to hydrolyze β-lactam antibiotics. Therefore, it does not serve the purpose of detecting specific molecules in ELISA. Alkaline phosphatase, horseradish peroxidase, and Β-galactosidase are preferred enzymes in ELISA due to their ability to produce a detectable signal when bound to specific molecules.

Correct Answer: A

Rationale: Rationale: 1. Spore-forming, Gram-positive rods: Characteristics shared by Clostridium and Bacillus. 2. Motile and gas production in nutrient broth: Clostridium perfringens is motile and produces gas, distinguishing it from Bacillus species. 3. Clostridium perfringens causes gas gangrene, correlating with gas production. 4. Bacillus anthracis causes anthrax, not related to wound infections. 5. Clostridium tetani causes tetanus, not associated with gas production. 6. Bacillus cereus causes food poisoning, not commonly associated with wound infections. Summary: - A is correct (Clostridium perfringens) due to motility, gas production, and wound infection correlation. - B (Bacillus anthracis) causes anthrax, not wound infections. - C (Clostridium tetani) causes tetanus, not gas production. - D (B

Correct Answer: A

Rationale: The correct answer is A: emergence. The term emergence refers to the process of a new infectious disease appearing and spreading within a population. It signifies the initial introduction and establishment of the disease in the new population. Explanation for other choices: B: Adoption does not accurately describe the process of a disease spreading within a new population. C: Inclusion is not a term commonly used to describe the spread of infectious diseases. D: Appearance is too vague and does not capture the complexity of the process of establishment and spreading of an infectious disease.

Correct Answer: B

Rationale: The correct answer is B: Absence of hemagglutination. In the reaction inhibition of hemagglutination, specific antibodies bind to antigens on red blood cells, preventing their agglutination. This results in the absence of visible clumping of red blood cells, which is known as hemagglutination. Therefore, the presence of specific antibodies is visualized by the absence of hemagglutination. Incorrect Choices: A: Absence of hemolysis - Hemolysis refers to the rupture of red blood cells, which is not relevant in the context of hemagglutination. C: Presence of hemagglutination - This is the opposite of what is expected when specific antibodies are present and inhibiting hemagglutination. D: Presence of hemolysis - Again, hemolysis is not directly related to the inhibition of hemagglutination by specific antibodies.