Rheumatic fever is an inflammatory disease and rare complication of:

Correct Answer: A

Rationale: Rheumatic fever is caused by untreated strep throat. Step 1: Strep throat is caused by Streptococcus bacteria. Step 2: If strep throat is not treated with antibiotics, it may lead to rheumatic fever due to the body's immune response attacking its own tissues. Summary: Gangrene, brucellosis, and tularemia are not associated with rheumatic fever.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Treponema pallidum and Borrelia burgdorferi are both spirochetes. 2. Spirochetes are characterized by their spiral shape and unique motility. 3. Both organisms exhibit corkscrew-like movement due to axial filaments. 4. Other choices are incorrect as Treponema and Borrelia are not gram-negative rods, cocci, or anaerobic cocci. Summary: The correct answer is D because Treponema pallidum and Borrelia burgdorferi are spirochetes, characterized by their spiral shape and motility. Other choices are incorrect as they do not accurately describe the characteristics of these organisms.

Correct Answer: D

Rationale: The correct answer is D because all the choices can contribute to hospital-acquired infections. New patients in the incubation period can spread infections, medical staff can inadvertently transmit infections, and contaminated medical instruments can also be a source of infections. Therefore, it is important to consider all these factors to prevent and control the spread of infections in a hospital setting.

Correct Answer: A

Rationale: The correct answer is A: Neisseria meningitidis. This is because Neisseria meningitidis is a Gram-negative diplococcus known to cause bacterial meningitis, presenting with fever, headache, and neck stiffness. It is a common cause of meningitis in young adults and teenagers. Streptococcus pneumoniae (B) is a Gram-positive bacteria and a common cause of bacterial pneumonia, not meningitis. Haemophilus influenzae (C) is a Gram-negative coccobacillus that can cause meningitis, but it is less common in adults. Klebsiella pneumoniae (D) is a Gram-negative bacillus known to cause pneumonia and urinary tract infections, not meningitis.

Correct Answer: A

Rationale: The correct answer is A: Robert Hooke. Hooke published Micrographia in 1665, showcasing detailed illustrations of insects, sponges, and plant cells under the microscope. Hooke's work was groundbreaking in advancing the field of microscopy. Van Leeuwenhoek is known for discovering microorganisms but did not publish Micrographia. Janssen and Needham were not associated with Micrographia. Therefore, A is the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Yersinia pestis. Yersinia pestis is the bacterium responsible for causing the plague, specifically the bubonic plague. It is transmitted through fleas and rodents. Escherichia coli (A) is a common gut bacterium, Clostridium difficile (C) causes antibiotic-associated diarrhea, and Staphylococcus aureus (D) is associated with skin infections, but they are not responsible for causing the plague.

Correct Answer: B

Rationale: The correct answer is B: biofilms. Biofilms refer to complex communities of microorganisms that adhere to surfaces. They are characterized by a protective matrix that allows the microorganisms to communicate and cooperate. Colonies (A) typically refer to groups of a single species, not diverse communities. Biospheres (C) refer to the regions of the Earth where life exists, not specific microbial communities. Flora (D) generally refers to the plant life in a particular region, not microbial communities on surfaces.

Correct Answer: D

Rationale: The correct answer is D, "All of these." Monotrichous bacteria have a single flagellum at one end, amphitrichous have flagella at both ends, and peritrichous have flagella distributed all over the surface. The answer D is correct because it includes all these possibilities based on flagella location. Monotrichous is incorrect as it only refers to a single flagellum, amphitrichous is incorrect as it only refers to flagella at both ends, and peritrichous is incorrect as it only refers to flagella all over the surface. Therefore, the correct answer encompasses all these options.

Correct Answer: C

Rationale: The correct answer is C: cytoplasmic membrane. The cytoplasmic membrane is the fluidlike portion of a cell that separates the cell's contents from the external environment. It regulates the passage of substances in and out of the cell, maintains cell shape, and provides protection. Rationale: 1. Cytosol (choice A) is the liquid component of the cytoplasm where organelles are suspended, not the fluidlike portion of the cell. 2. Nucleoplasm (choice B) refers to the liquid component of the nucleus, not the entire cell. 3. Inclusion (choice D) refers to non-living substances within the cell that are not considered the fluidlike portion. Summary: The cytoplasmic membrane is the correct answer as it encompasses the entire cell and is responsible for maintaining cell integrity and regulating transport. Choices A, B, and D are incorrect as they do not represent the fluidlike portion of the cell.