microbiology chapter 10 test bank

Correct Answer: B

Rationale: The correct answer is B: FALSE. The statement is incorrect because the secondary immune response is actually faster than the primary immune response. This is due to memory cells that are formed during the primary response, allowing for a quicker and more robust reaction upon re-exposure to the same antigen. The secondary response produces more antibodies and is more effective in clearing the pathogen. Choice A is incorrect because the secondary response is faster, not slower. Choice C is incorrect because the statement is objectively false, regardless of the situation. Choice D is incorrect as the correct answer is B.

Correct Answer: D

Rationale: The correct answer is D: Agar media. Influenza viruses cannot be isolated in agar media because they require specific conditions present in laboratory animals, embryonated eggs, or cell cultures for successful isolation and propagation. Agar media lack the necessary components and environment needed for influenza virus replication. In laboratory animals, such as mice, the viruses can replicate and cause infection. Embryonated eggs provide a suitable environment for influenza virus growth and isolation due to the presence of necessary nutrients and factors. Cell cultures offer controlled conditions for virus propagation and study, making them a valuable tool in influenza virus research.

Correct Answer: A

Rationale: The correct answer is A: gram-positive cocci. Staphylococci and streptococci are both types of bacteria that have a thick layer of peptidoglycan in their cell walls, which retains the crystal violet stain in the Gram staining process, making them appear purple under a microscope, hence classified as gram-positive cocci. Choice B: gram-negative cocci is incorrect as staphylococci and streptococci are not classified as gram-negative bacteria based on their cell wall structure. Choice C: spirochetes is incorrect as spirochetes are spiral-shaped bacteria with unique motility mechanisms, distinct from the spherical shape of cocci. Choice D: anaerobic gram-negative cocci is incorrect as staphylococci and streptococci are not classified as anaerobic bacteria and do not have the typical characteristics of gram-negative cocci.

Correct Answer: A

Rationale: The correct answer is A: 1 chromosome. Bacterial cells typically have a singular circular chromosome that contains their genetic material. This chromosome is essential for the cell's survival and contains all the necessary genetic information for its functions. Choices B, C, and D are incorrect because they refer to the chromosome numbers found in human cells (23 pairs or 46 individual chromosomes). Bacteria, being prokaryotic organisms, have a simpler genetic makeup compared to eukaryotic organisms like humans, hence they possess only one chromosome.

Correct Answer: A

Rationale: The correct answer is A: Clostridium perfringens. This bacterium is Gram-positive, spore-forming, anaerobic, and produces gas. Clostridium perfringens is commonly associated with wound infections due to its ability to produce gas gangrene. Choice B: Bacillus anthracis is also a Gram-positive, spore-forming bacterium, but it does not typically produce gas in wound infections. Choice C: Clostridium botulinum is a spore-forming, anaerobic bacterium, but it is associated with foodborne botulism rather than wound infections. Choice D: Clostridium tetani is a spore-forming, anaerobic bacterium that causes tetanus, but it does not produce gas in wound infections.