Nursing Elites

1. What does the P-wave in an ECG correspond to?

• A. Atrial repolarization
• B. Depolarization of SA node
• C. Ventricular depolarization
• D. Ventricular repolarization

Correct answer: B

Rationale: The P-wave in an ECG represents the depolarization of the SA node and the atria, not atrial repolarization. Choice C, ventricular depolarization, is incorrect because the P-wave does not correspond to ventricular activity. Choice D, ventricular repolarization, is also incorrect as the P-wave does not depict ventricular repolarization. The correct interpretation is that the P-wave signifies the initiation of the electrical impulse at the SA node and subsequent atrial depolarization, making option B the correct answer.

2. How many moles of oxygen are required to completely react with 5 moles of propane (C3H8) in the combustion reaction?

• A. 5 moles
• B. 10 moles
• C. 15 moles
• D. 20 moles

Correct answer: C

Rationale: In the balanced chemical equation for the combustion of propane (C3H8): C3H8 + 5O2 → 3CO2 + 4H2O, 1 mole of propane (C3H8) reacts with 5 moles of oxygen (O2). To determine the moles of oxygen required to react with 5 moles of propane, we use the molar ratio: 5 moles propane x 5 moles oxygen / 1 mole propane = 25 moles oxygen. However, since the question specifically asks for the moles of oxygen needed to react with 5 moles of propane, the correct answer is 15 moles of oxygen. Choice A, 5 moles, is incorrect because this is the amount of propane provided, not the oxygen required. Choice B, 10 moles, is incorrect as it does not correspond to the molar ratio in the balanced equation. Choice D, 20 moles, is incorrect as it is not in line with the stoichiometry of the reaction.

3. Which respiratory structure is responsible for the production of mucus to trap particles and for the movement of cilia to sweep mucus and trapped particles out of the respiratory tract?

• A. Trachea
• B. Larynx
• C. Bronchi
• D. Respiratory epithelium

Correct answer: D

Rationale: The respiratory epithelium is the correct answer because it is the tissue lining the respiratory tract responsible for producing mucus to trap particles and containing cilia that sweep the mucus and trapped particles out of the respiratory tract. The trachea, larynx, and bronchi are all structures within the respiratory system but do not specifically carry out the functions described in the question. The trachea is a passage for air, the larynx is involved in sound production and protecting the airway, and the bronchi are airway passages that branch from the trachea to the lungs. Only the respiratory epithelium fits the description of producing mucus and utilizing cilia for particle removal in the respiratory tract.

4. What is the process of cells dividing to produce new cells called?

• A. Cell division
• B. Cell differentiation
• C. Cell growth
• D. Cell regeneration

Correct answer: A

Rationale: Cell division is the correct answer. It is the process by which a parent cell divides into two or more daughter cells, enabling growth, repair, and reproduction in living organisms. This process ensures that genetic material is accurately passed on to the new cells. Cell differentiation refers to the specialization of cells to perform specific functions, while cell growth is the increase in size or mass of a cell. Cell regeneration involves replacing damaged or lost cells with new ones, where cell division plays a role but is not the primary process of generating new cells. Therefore, in the context of cells producing new cells, cell division is the accurate term.

5. Which of the following is an example of a salt?

• A. Sodium hydroxide (NaOH)
• B. Hydrochloric acid (HCl)
• C. Sodium chloride (NaCl)
• D. Sulfuric acid (H₂SO₄)

Correct answer: C

Rationale: Sodium chloride (NaCl) is an example of a salt. Salts are ionic compounds formed by the reaction of an acid with a base. In this case, sodium chloride is formed by the reaction of sodium hydroxide (a base) with hydrochloric acid (an acid). Sodium hydroxide (NaOH), hydrochloric acid (HCl), and sulfuric acid (H₂SO₄) are not salts because they are not formed by the neutralization reaction of an acid and a base, which is a characteristic of salts.

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