Nursing Elites

1. What is the scientific unit used to measure the radioactivity of a substance?

• A. Becquerel (Bq)
• B. Joule (J)
• C. Newton (N)
• D. Kelvin (K)

Correct answer: A

Rationale: The correct answer is A: Becquerel (Bq). The Becquerel (Bq) is the scientific unit used to measure the radioactivity of a substance. It is named after Henri Becquerel, who discovered radioactivity. The Joule (J) is the unit of energy, Newton (N) is the unit of force, and Kelvin (K) is the unit of temperature. When measuring radioactivity, the Becquerel is used to quantify the rate of radioactive decay in a substance. Choices B, C, and D are incorrect as they represent units for energy, force, and temperature, respectively, not radioactivity.

2. Which of the following structures is found in the nucleus of a cell?

• A. Mitochondria
• B. Endoplasmic reticulum
• C. Chromosomes
• D. Ribosomes

Correct answer: C

Rationale: Chromosomes, which contain genetic information, are found in the nucleus of a cell. They play a crucial role in cell division, gene expression, and inheritance. Mitochondria, responsible for energy production, are located in the cytoplasm, not the nucleus. The endoplasmic reticulum is mainly involved in protein and lipid synthesis and is not a component of the nucleus. Ribosomes, essential for protein synthesis, are found in the cytoplasm and on the endoplasmic reticulum, but not in the nucleus.

3. Why is warming up before exercise important?

• A. To prevent dehydration
• B. To prevent muscle soreness
• C. To prevent increased heart rate
• D. To prevent low blood sugar

Correct answer: B

Rationale: Warming up before exercise is crucial to prevent muscle soreness. It helps by increasing blood flow to the muscles, improving flexibility, and preparing the body for physical activity. Dehydration, increased heart rate, and low blood sugar are not directly prevented by warming up before exercise. Dehydration is prevented by proper hydration before and during exercise; increased heart rate is a normal physiological response to exercise; and low blood sugar is managed through proper nutrition and timing of meals before physical activity.

4. How many molecules of NADPH and ATP are required to reduce 6 molecules of CO2 to glucose via photosynthesis?

• A. 6 NADPH and 9 ATP
• B. 12 NADPH and 18 ATP
• C. 18 NADPH and 24 ATP
• D. 24 NADPH and 36 ATP

Correct answer: B

Rationale: During photosynthesis, 12 molecules of NADPH and 18 molecules of ATP are required to reduce 6 molecules of CO2 to glucose. NADPH and ATP are essential energy carriers in the process of photosynthesis. Choice A is incorrect because it underestimates the required molecules of both NADPH and ATP. Choices C and D overestimate the number of molecules needed, making them incorrect answers.

5. Isotopes are variants of a single element that differ in:

• A. Having the same number of protons but varying numbers of neutrons
• B. Having the same number of neutrons but varying numbers of protons
• C. Having the same mass but different atomic numbers
• D. None of the above

Correct answer: A

Rationale: Isotopes are variants of a single element that have the same number of protons, the defining characteristic of an element. They differ in the number of neutrons they possess, leading to isotopes having different atomic masses while retaining the same chemical properties. Choice B is incorrect because isotopes have the same number of neutrons and differ in the number of protons. Choice C is incorrect because isotopes have different masses due to varying numbers of neutrons, not different atomic numbers. Choice D is incorrect as isotopes do differ in the number of neutrons they possess.

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