Nursing Elites

1. What is the primary function of ribosomes in a cell?

• A. Protein synthesis
• B. DNA replication
• C. Cell division
• D. Lipid synthesis

Correct answer: A

Rationale: The correct answer is A: Protein synthesis. Ribosomes are the cellular organelles responsible for protein synthesis. They read the messenger RNA (mRNA) and translate the genetic information into specific proteins. This process is essential for building and maintaining the structures and functions of the cell. Choice B, DNA replication, is incorrect because ribosomes are not involved in replicating DNA; that process occurs in the nucleus. Choice C, cell division, is incorrect as ribosomes are not directly involved in cell division but rather in protein synthesis. Choice D, lipid synthesis, is also incorrect as ribosomes are not responsible for synthesizing lipids, which primarily occurs in the endoplasmic reticulum and other organelles.

2. Salts are formed by the reaction between:

• A. Two acids
• B. An acid and a base
• C. Two bases
• D. A metal and a nonmetal only

Correct answer: B

Rationale: Salts are formed by the reaction between an acid and a base. This reaction is known as a neutralization reaction. In this reaction, the acid donates a proton (H+) to the base, resulting in the formation of water and a salt as the products. Choice A is incorrect because salts are not formed by the reaction of two acids. Choice C is incorrect as salts are not produced by the reaction of two bases. Choice D is incorrect because while salts can be formed from the reaction between a metal and a nonmetal, it is not the only way salts are produced.

3. What is the name of the muscular ring that controls the passage of food from the esophagus to the stomach?

• A. Pyloric sphincter
• B. Cardiac sphincter
• C. Ileocecal valve
• D. Sphincter of Oddi

Correct answer: B

Rationale: The correct answer is the Cardiac sphincter (lower esophageal sphincter). It is situated at the junction of the esophagus and the stomach, controlling the passage of food into the stomach. The cardiac sphincter opens and closes to regulate the flow of food and prevent reflux. The pyloric sphincter, on the other hand, is located between the stomach and the small intestine, not the esophagus and stomach. The ileocecal valve is positioned between the small and large intestines, while the Sphincter of Oddi is found in the duodenum, not between the esophagus and stomach.

4. Which of the following is an example of a decomposition reaction?

• A. 2H2 + O2 → 2H2O
• B. CaCO3 → CaO + CO2
• C. 2Na + Cl2 → 2NaCl
• D. N2 + 3H2 → 2NH3

Correct answer: B

Rationale: A decomposition reaction involves a single compound breaking down into two or more simpler substances. In option B, CaCO3 breaks down into CaO and CO2, making it an example of a decomposition reaction. Options A, C, and D involve different types of chemical reactions such as synthesis, combination, and combustion, respectively. Option A represents a synthesis reaction, where two elements combine to form a compound. Option C demonstrates a combination reaction, where two elements combine to form a compound. Option D is an example of a synthesis reaction, where two reactants combine to form a single compound. It is important to recognize the specific characteristics of each type of chemical reaction to identify the correct example of decomposition reaction, where a compound breaks down into simpler products.

5. What is the process by which a solid changes directly into a liquid?

• A. Melting
• B. Condensation
• C. Sublimation
• D. Deposition

Correct answer: A

Rationale: The correct answer is A: Melting. Melting is the process through which a solid substance changes directly into a liquid. Choice B, Condensation, is the transition from gas to liquid. Choice C, Sublimation, refers to the direct change from solid to gas. Choice D, Deposition, is the direct transition from gas to solid, not from solid to liquid as in the question.

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