Nursing Elites

1. In the reaction 4Al + 3O2 → 2Al2O3, what is the mole ratio of aluminum to oxygen?

• A. 4:3
• B. 2:3
• C. 3:2
• D. 3:4

Correct answer: A

Rationale: The balanced chemical equation shows that 4 moles of aluminum react with 3 moles of oxygen to produce 2 moles of aluminum oxide. Therefore, the mole ratio of aluminum to oxygen is 4:3. Choice B (2:3) is incorrect because it does not reflect the correct ratio based on the balanced equation. Choice C (3:2) and Choice D (3:4) are also incorrect as they do not represent the correct mole ratio of aluminum to oxygen according to the balanced chemical equation.

2. Acids are generally characterized by a sour taste and the ability to:

• A. Turn litmus paper red
• B. Conduct electricity in solution
• C. Neutralize bases
• D. React explosively with metals

Correct answer: C

Rationale: Acids are known for their sour taste and their ability to neutralize bases, which is a defining characteristic of their acidic nature. When acids neutralize bases, salts and water are formed, highlighting the unique property of acids. The other options are incorrect: Option A, 'Turn litmus paper red,' is a test for acidity but not a defining characteristic of acids; Option B, 'Conduct electricity in solution,' pertains to the electrolytic properties of acids rather than their defining trait; Option D, 'React explosively with metals,' is not a general characteristic of acids. Therefore, the correct feature associated with acids is their capability to neutralize bases, making option C, 'Neutralize bases,' the correct answer.

3. What is the medical term for heartburn, a burning sensation in the chest caused by stomach acid?

• A. Dysphagia
• B. Gastroesophageal reflux disease (GERD)
• C. Peptic ulcer
• D. Ulcerative colitis

Correct answer: B

Rationale: A) Dysphagia refers to difficulty swallowing and is not specifically related to heartburn. B) Gastroesophageal reflux disease (GERD) is the medical term for heartburn, which is a burning sensation in the chest caused by stomach acid flowing back up into the esophagus. C) Peptic ulcer is a sore that develops on the lining of the stomach, small intestine, or esophagus, and it can cause symptoms such as abdominal pain, not specifically heartburn. D) Ulcerative colitis is a type of inflammatory bowel disease that affects the colon and rectum, and it does not typically cause heartburn.

4. Which group of antibiotics targets the cell wall of bacteria?

• A. Penicillins
• B. Tetracyclines
• C. Macrolides
• D. Fluoroquinolones

Correct answer: A

Rationale: Penicillins are a group of antibiotics that target the bacterial cell wall by inhibiting the synthesis of peptidoglycan, a vital component of the cell wall. This inhibition weakens the cell wall, leading to bacterial cell lysis and death. Penicillins are particularly effective against Gram-positive bacteria due to their mechanism of action. Tetracyclines (B) inhibit protein synthesis, Macrolides (C) interfere with bacterial ribosomes, and Fluoroquinolones (D) target bacterial DNA gyrase and topoisomerase IV. Unlike Penicillins, these antibiotics do not directly target the cell wall of bacteria.

5. How do killer T cells recognize infected cells?

• A. The B cells flag the infected cells with amino acids.
• B. Tiny bits of the virus's RNA are left around the cell.
• C. Macrophages show up to help consume the infected cell.
• D. The T cells have receptors that recognize the proteins the virus leaves on the surface of the cell.

Correct answer: D

Rationale: Killer T cells recognize infected cells by detecting viral proteins displayed on the surface of these cells. The T cells possess receptors specifically designed to identify these viral proteins, allowing them to target and eliminate the infected cells. Choice A is incorrect because B cells are not directly involved in the recognition process of infected cells by killer T cells. Choice B is incorrect because tiny bits of the virus's RNA being left around the cell is not how killer T cells primarily recognize infected cells. Choice C is incorrect because while macrophages play a role in immune responses, they do not directly assist in the recognition of infected cells by killer T cells.

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