Nursing Elites

1. 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: b

Rationale: The balanced equation is C3H8 + 5O2 → 3CO2 + 4H2O, indicating a 5:10 ratio between moles of oxygen and moles of propane.

2. The neutral theory of molecular evolution proposes that:

• A. Most mutations in DNA are selectively neutral and do not affect an organism's fitness.
• B. All mutations are beneficial and contribute to the adaptation of a population.
• C. The rate of evolution is primarily driven by strong directional selection pressures.
• D. Genetic drift plays a negligible role in shaping genetic variation within populations.

Correct answer: A

Rationale: Rationale: A) The neutral theory of molecular evolution, proposed by Motoo Kimura in the 1960s, suggests that the majority of mutations that occur in DNA are selectively neutral, meaning they do not have a significant impact on an organism's fitness. These neutral mutations are not subject to natural selection and are allowed to accumulate in populations over time. This theory helps explain the high levels of genetic variation observed within populations. B) Option B is incorrect because not all mutations are beneficial. Mutations can be neutral, harmful, or beneficial, and the neutral theory specifically focuses on the idea that many mutations are neutral in their effects. C) Option C is incorrect because the neutral theory suggests that evolution is not primarily driven by strong directional selection pressures. Instead, it emphasizes the role of genetic drift and the accumulation of neutral mutations in shaping genetic variation. D) Option D is incorrect because

3. What property of a wave is responsible for determining its energy?

• A. Amplitude
• B. Wavelength
• C. Frequency
• D. Velocity

Correct answer: a

Rationale: The amplitude of a wave determines its energy, with higher amplitudes corresponding to higher energy levels.

4. Which of the following glands is NOT directly controlled by the pituitary gland?

• A. Thyroid gland
• B. Adrenal glands
• C. Pancreas (islets of Langerhans)
• D. Parathyroid glands

Correct answer: C

Rationale: The correct answer is C. The pituitary gland is often referred to as the 'master gland' because it secretes hormones that control the functions of other endocrine glands. The thyroid gland (A), adrenal glands (B), and parathyroid glands (D) are directly controlled by the pituitary gland through the release of specific hormones. However, the pancreas, specifically the islets of Langerhans (C), is not directly controlled by the pituitary gland. The pancreas is regulated by hormones such as insulin and glucagon, which are not secreted by the pituitary gland. Therefore, option C is the correct answer as it is not directly influenced by the pituitary gland's hormonal regulation.

5. A reaction between an acid and a base is known as:

• A. Precipitation
• B. Neutralization
• C. Oxidation-reduction
• D. Photolysis

Correct answer: B

Rationale: When an acid and a base react, they neutralize each other's properties

6. Balance the following redox reaction in acidic solution: I⁻ (aq) + Cr₂O₇²⁻ (aq) -> I₂ (aq) + Cr³⁺ (aq). Identify the oxidizing agent and reducing agent.

• A. I⁻ is oxidized, Crâ‚‚O₇²⁻ is reduced
• B. I⁻ is reduced, Crâ‚‚O₇²⁻ is oxidized.
• C. Both I⁻ and Crâ‚‚O₇²⁻ are oxidized.
• D. Both I⁻ and Crâ‚‚O₇²⁻ are reduced.

Correct answer: A

Rationale: . I⁻ loses an electron (oxidation), Cr₂O₇²⁻ gains electrons (reduction).

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