The nurse is preparing an injection for an individual who requires passive immunity. In which situation would passive immunity be indicated?

Correct Answer: C

Rationale: Passive immunity is indicated when an individual needs immediate protection with ready-made antibodies after exposure to pathogens. This is the correct answer (C) as it provides immediate defense without waiting for the body to produce its antibodies. Choice A is incorrect because passive immunity is temporary, not permanent. Choice B is incorrect as it addresses treating allergic reactions, not providing immunity. Choice D is incorrect as a booster dose stimulates the body to produce its antibodies, not providing ready-made antibodies.

Correct Answer: A

Rationale: The correct answer is A because bacterial cytoplasmic membranes typically contain ester-linked phospholipids but no sterols. Ester-linked phospholipids are the main component of bacterial cell membranes, providing structure and function. Sterols, like cholesterol, are not commonly found in bacterial membranes. Choice B is incorrect because sterols are not present in bacterial membranes. Choice C is incorrect because ether-linked phospholipids are more commonly found in archaea, not bacteria. Choice D is incorrect because sulfolipids and glycolipids are not primary components of bacterial cytoplasmic membranes.

Correct Answer: d

Rationale: The correct answer is D because in prokaryotes, 50s and 30s ribosomal subunits combine to form the 70s ribosome, which is necessary for protein synthesis. Firstly, ribosomes are composed of two subunits, and in prokaryotes, these are the 50s and 30s subunits. Secondly, these subunits come together during translation to form the functional ribosome. Therefore, these ribosomal subunits are indeed necessary for protein synthesis in prokaryotes. A: Incorrect. Translation can begin before transcription is finished in prokaryotes due to their lack of a nuclear membrane. B: Incorrect. Messenger RNA in prokaryotes is co-linear with the DNA template as they do not undergo RNA splicing like eukaryotes. C: Incorrect. In prokaryotes, the ribosomal RNA present is the 16s, 23s, and 5s, not 28s.

Correct Answer: D

Rationale: The correct answer is D because in the electron transport chain, protons (H⁺) are pumped across the membrane to create a proton gradient. This gradient is utilized by ATP synthase to produce ATP. Therefore, protons go into solution outside the cytoplasmic membrane. Choices A and B are incorrect because protons do not simply stay in the cytoplasm or get taken back by NAD and FAD. Choice C is incorrect as protons do not directly form water when carried by cytochromes.

Correct Answer: C

Rationale: Rationale for Answer C: 1. Allergen exposure triggers B cells to produce IgE antibodies specific to the allergen. 2. IgE antibodies bind to mast cells sensitizing them. 3. Upon re-exposure to allergen, allergen binds to IgE on mast cells. 4. This triggers release of histamine and other chemicals causing allergic symptoms. Summary: - Choice A: Incorrect because B cells do not produce IgE antibodies before allergen exposure. - Choice B: Incorrect because IgE antibodies are produced by B cells, not the other way around. - Choice D: Incorrect because histamine is released after allergen binds to IgE on sensitized mast cells.