Reactions where small precursor molecules are assembled into larger organic molecules are

Correct Answer: A

Rationale: The correct answer is A: anabolic. Anabolic reactions involve the synthesis of larger organic molecules from smaller precursor molecules. This process requires energy input and is essential for growth and repair in living organisms. Choice B: Catabolic reactions involve the breakdown of larger molecules into smaller ones, releasing energy in the process. This is the opposite of what is described in the question. Choice C: Metabolic is a broad term that encompasses all chemical processes in living organisms, including both anabolic and catabolic reactions. It is not specific to the assembly of small molecules into larger ones. Choice D: "Any of the above" is incorrect because only anabolic reactions specifically involve the assembly of small precursor molecules into larger organic molecules.

Correct Answer: A

Rationale: Step 1: Ziehl-Neelsen staining is a type of acid-fast staining used to detect acid-resistant bacteria like Mycobacterium species. Step 2: Acid-resistant bacteria have a high lipid content in their cell walls, making them resist decolorization with acid-alcohol. Step 3: Mycobacterium species, such as M. tuberculosis and M. leprae, are examples of acid-resistant bacteria. Step 4: Spores are not typically stained using Ziehl-Neelsen staining, making choice B incorrect. Step 5: Metachromatic bodies are stained using specific techniques like Albert's stain, not Ziehl-Neelsen staining, making choice C incorrect. Summary: Ziehl-Neelsen staining is specifically used for acid-resistant bacteria detection, making choice A the correct answer. Choices B and C are incorrect as they do not align with the purpose of Ziehl-Neelsen staining. Choice D is incorrect as Ziehl

Correct Answer: C

Rationale: The correct answer is C: Staphylococcus saprophyticus. The rationale is that Staphylococcus saprophyticus is the only one among the listed species that is known to be resistant to novobiocin. This resistance is due to the specific mechanism of action of novobiocin, which targets DNA gyrase, and Staphylococcus saprophyticus possesses an altered DNA gyrase enzyme that renders it resistant to the antibiotic. Staphylococcus aureus and Staphylococcus epidermidis are susceptible to novobiocin, making choices A and B incorrect. Choice D, "none of the listed," is also incorrect as Staphylococcus saprophyticus is indeed resistant to novobiocin.

Correct Answer: A

Rationale: The correct answer is A: Doxycycline. It is a broad-spectrum antibiotic effective against a wide range of bacteria, including those causing infections like Lyme disease and pneumonia. Doxycycline is often the first-line treatment for these infections due to its efficacy and low risk of resistance. Chloramphenicol (B) has serious side effects and is reserved for specific cases. Penicillin (C) is not effective against all bacteria and may not cover the specific infection. Streptomycin (D) is mainly used for certain types of bacterial infections and is not the optimal choice for the conditions mentioned in the question.

Correct Answer: A

Rationale: Rationale: 1. Gram-positive cocci in clusters point to Staphylococcus or Micrococcus. 2. Catalase-positive eliminates Streptococcus. 3. Coagulase-positive distinguishes Staphylococcus aureus. 4. Thus, the causative agent is Staphylococcus aureus. Summary: - B: Streptococcus pyogenes is catalase-negative. - C: Enterococcus faecalis is catalase-negative. - D: Micrococcus luteus is catalase-positive but coagulase-negative.

Correct Answer: D

Rationale: The correct answer is D: polyomavirus infections. Polyomavirus infections do not typically recur during pregnancy because once the virus infects the body, it remains latent without causing recurrent infections. In contrast, choices A, B, and C can recur during pregnancy due to their ability to reactivate from latency or reinfect the host. Epstein-Barr virus infections (choice A) can lead to infectious mononucleosis, herpes simplex virus infections (choice B) can cause recurrent genital or oral herpes outbreaks, and streptococcal infections (choice C) can result in recurrent throat or skin infections.

Correct Answer: C

Rationale: Rationale: 1. Bacillus anthracis and Clostridium tetani are both spore-forming bacteria. 2. Spores allow them to survive harsh conditions like extreme heat or lack of nutrients. 3. Choice C is correct because both A and B (Bacillus anthracis and Clostridium tetani) produce spores. 4. Choice D is incorrect as both bacteria mentioned are known to produce spores, enabling them to survive in extreme conditions.

Correct Answer: B

Rationale: The correct answer is B: Hantavirus. Hantaviruses are not arthropod-borne, unlike the other choices. Hantaviruses are transmitted to humans primarily through contact with rodent urine, feces, or saliva. Phlebovirus (A), Nairovirus (C), and Uukuvirus (D) are all bunyaviruses that are transmitted by arthropod vectors such as mosquitoes or ticks. Therefore, Hantavirus is the correct answer as it is not transmitted by arthropods.

Correct Answer: A

Rationale: The correct answer is A because it accurately describes the major morphological forms of bacteria. Cocci are spherical, rod-shaped bacteria are called bacilli, and curved bacteria are spirilla. Staphylococci, streptococci, and diplococci are specific types of cocci, not major morphological forms. Basicili and spiralis are not common morphological forms of bacteria. Option D is incorrect as the other choices do represent major morphological forms of bacteria.