Which of the following characteristics does not refer to the flu vaccine?

Correct Answer: D

Rationale: The correct answer is D because the flu vaccine mainly stimulates systemic immunity, not local immunity. Systemic immunity refers to the immune response throughout the body, while local immunity is specific to a certain area. Choice A is incorrect because the flu vaccine is indeed recommended. Choice B is incorrect as the flu vaccine can be a subunit vaccine, containing only specific antigens. Choice C is incorrect as the flu vaccine is typically administered parenterally, meaning through injection, nasal spray, or oral routes.

Correct Answer: A

Rationale: The correct answer is A: chloroplasts. Algae and plant cells have chloroplasts, which are responsible for photosynthesis. This organelle contains chlorophyll, enabling these cells to convert sunlight into energy. Mitochondria (B) are found in all eukaryotic cells, not specific to algae and plants. Vacuoles (C) are present in plant cells but also in other eukaryotic cells. Vesicles (D) are membrane-bound sacs found in all types of cells for transport and storage purposes, not unique to algae and plants. Therefore, A is the correct answer.

Correct Answer: C

Rationale: The correct answer is C because transcription is the process in which messenger RNA transcripts are produced from DNA. During transcription, a specific segment of DNA is transcribed into mRNA by RNA polymerase. Choice A is incorrect because translation, not transcription, involves converting mRNA into protein. Choice B is incorrect as it describes DNA replication, not transcription. Choice D is incorrect because it refers to translation, where polypeptides are synthesized from mRNA. Therefore, choice C is the correct answer as it accurately describes the process of transcription.

Correct Answer: A

Rationale: The correct answer is A: Capsule. The capsule is a mucous structure tightly bound to the bacterial cell wall. It helps bacteria evade the host immune system and provides protection. The other choices are incorrect because: B) Spores are resistant structures formed by some bacteria for survival, C) Flagella are long, whip-like structures for movement, and D) Filaments are long, thin structures found in some bacteria.

Correct Answer: B

Rationale: The correct answer is B: Malaria. Fever developing 2 weeks post-blood transfusion is characteristic of malaria due to the incubation period of the parasite. Trypanosomiasis presents earlier, amebiasis usually causes GI symptoms, and toxoplasmosis typically manifests with flu-like symptoms. Malaria is the most likely cause based on the timing and clinical presentation.

Correct Answer: A

Rationale: The correct answer is A: Clostridium botulinum. This bacterium is responsible for causing botulism due to its production of botulinum toxin, which is one of the most potent neurotoxins known. Clostridium botulinum thrives in anaerobic conditions like improperly canned foods. Staphylococcus aureus (B), Bacillus anthracis (C), and Pseudomonas aeruginosa (D) do not produce the botulinum toxin and are not associated with botulism. Staphylococcus aureus is known for causing food poisoning, Bacillus anthracis for anthrax, and Pseudomonas aeruginosa for various infections, but not botulism.

Correct Answer: A

Rationale: The correct answer is A: Propionibacterium shermanii. This bacterium is used in the production of certain types of cheese, such as Swiss cheese, to create the characteristic holes and flavor. Propionibacterium produces carbon dioxide gas during fermentation, forming the holes in the cheese. Acetobacter aceti (B) is used in vinegar production. Giardia (C) is a parasite that causes gastrointestinal issues, not used in cheese production. Fusobacterium (D) is a type of bacteria associated with infections in humans, not used in cheese production.

Correct Answer: A

Rationale: The correct answer is A: Alexander Fleming. He discovered the antibiotic properties of Penicillium in 1928. Fleming observed that a mold called Penicillium notatum inhibited the growth of bacteria, leading to the discovery of penicillin. Louis Pasteur is known for his work on pasteurization and microbiology, not penicillin. Joseph Lister is known for pioneering antiseptic surgery techniques. Edward Jenner is known for developing the smallpox vaccine, not penicillin. Fleming's discovery revolutionized medicine by introducing the first antibiotic, penicillin, which has saved countless lives.

Correct Answer: C

Rationale: The correct answer is C: Weakly bound to the cell wall. The glycocalyx in bacteria is a protective layer that can be loosely attached to the cell wall or membrane. This loose attachment allows for flexibility and protection against desiccation and immune responses. Choice A is incorrect because the glycocalyx is not strongly bound to the cell wall, as it needs to be able to be shed easily for bacteria to escape host immune responses. Choice B is incorrect because the glycocalyx is not directly involved in bacterial movement, but rather serves as a protective barrier. Choice D is incorrect as the glycocalyx does play a role in bacterial physiology.