Nursing Elites

1. What effect does doubling the net force applied to an object have on its acceleration, assuming mass remains constant?

• A. Acceleration doubles
• B. Acceleration is halved
• C. Acceleration remains the same
• D. Acceleration quadruples

Correct answer: a

Rationale: According to Newton's second law (F = ma), if mass remains constant and force doubles, acceleration also doubles.

2. Which type of energy is associated with the random motion of particles in a substance?

• A. Potential energy
• B. Mechanical energy
• C. Thermal energy
• D. Chemical energy

Correct answer: c

Rationale: Thermal energy is related to the random motion of particles in a substance and is associated with temperature.

3. Which hormone, produced by the pancreas, acts in opposition to insulin by increasing blood sugar levels?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Thyroxine

Correct answer: b

Rationale: The correct answer is B: Glucagon. Glucagon is a hormone produced by the pancreas that acts in opposition to insulin. When blood sugar levels are low, glucagon stimulates the liver to convert stored glycogen into glucose, which raises blood sugar levels. Insulin, on the other hand, lowers blood sugar levels by promoting the uptake and storage of glucose. Cortisol, produced by the adrenal glands, plays a role in stress response and metabolism but does not directly regulate blood sugar levels. Thyroxine, produced by the thyroid gland, regulates metabolism but does not directly affect blood sugar levels. Therefore, glucagon is the hormone that acts in opposition to insulin by increasing blood sugar levels.

4. The body's first line of defense against pathogens is the innate immune system. Which of the following is NOT a component of the innate immune system?

• A. Physical barriers like skin and mucous membranes
• B. Phagocytes that engulf and destroy pathogens
• C. Inflammatory response to isolate and contain infection
• D. Production of antibodies specific to a particular pathogen

Correct answer: D

Rationale: The innate immune system is the body's first line of defense against pathogens and includes physical barriers like skin and mucous membranes, phagocytes that engulf and destroy pathogens, and the inflammatory response to isolate and contain infection. However, the production of antibodies specific to a particular pathogen is a function of the adaptive immune system, not the innate immune system. The innate immune system provides immediate, nonspecific defenses, while the adaptive immune system generates specific responses to target pathogens. Therefore, option D is NOT a component of the innate immune system, making it the correct answer in this question.

5. Half-life refers to the characteristic time it takes for:

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: The correct answer is D: An isotope to decay by half of its initial quantity. The half-life of a substance is the time it takes for half of the initial quantity of radioactive atoms to decay. This is a characteristic property of each radioactive isotope and is used to determine the rate of decay of a substance. Option A is incorrect because radioactive intensity does not completely disappear in half-life, it only decreases by half. Options B and C are unrelated to the concept of half-life and do not accurately describe its definition.

6. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

• A. Na
• B. H2O
• C. NaOH
• D. H2

Correct answer: a

Rationale: Sodium is the limiting reactant because it runs out first in a 1:1 ratio with water.

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