Rocky Mountain spotted fever is caused by:

Correct Answer: B

Rationale: The correct answer is B: Rickettsia rickettsii. Rocky Mountain spotted fever is caused by Rickettsia rickettsii, a bacterium transmitted by ticks. This pathogen primarily affects the endothelial cells of blood vessels, leading to vasculitis. Borrelia burgdorferi (choice A) causes Lyme disease, not Rocky Mountain spotted fever. Rickettsia prowazekii (choice C) causes epidemic typhus, and Ehrlichia chaffeensis (choice D) causes human monocytic ehrlichiosis, both of which are distinct from Rocky Mountain spotted fever. Therefore, the correct choice is B based on the specific etiology of the disease.

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: Binary fission is a form of asexual reproduction where a single organism divides into two equal parts. Bacteria reproduce through binary fission, splitting into two identical daughter cells. Viruses are not considered living organisms and reproduce by infecting host cells. Fungi reproduce through spores or sexual reproduction. Helminths are parasitic worms that reproduce sexually. Therefore, the correct answer is B, bacteria, as they specifically utilize binary fission for reproduction.

Correct Answer: B

Rationale: Decontamination is the reduction or removal of unwanted chemical or biological agents to make an area safe. This includes cleaning, disinfecting, or sterilizing to eliminate harmful substances. Choice A is incorrect as decontamination doesn't necessarily involve killing all microorganisms. Choice C is incorrect as it focuses on stopping growth, not removing existing contaminants. Choice D is incorrect as it specifically mentions vegetative organisms, which may not cover all types of contaminants that need to be removed during decontamination. Thus, the correct answer is B as it accurately describes the process of decontamination.

Correct Answer: D

Rationale: The correct answer is D (4) because biosafety levels range from 1 to 4, each corresponding to the level of containment required when handling different types of organisms. BSL-1 is for low-risk agents, while BSL-4 is for dangerous pathogens. Choice A (1) is incorrect as there are multiple levels, not just one. Choice B (2) and C (3) are incorrect as they do not account for all the levels of biosafety required for handling various organisms. Therefore, D is the correct answer as it encompasses the full range of biosafety levels.