Nursing Elites

1. Which of the following is the antiparticle of a neutron?

• A. Antineutrino
• B. Positron
• C. Antiproton
• D. Electron

Correct answer: C

Rationale: The antiparticle of a neutron is an antineutron, which is composed of an antiproton and an antineutrino. The antineutrino (choice A) is not the antiparticle of a neutron. A positron (choice B) is the antiparticle of an electron, not a neutron. An electron (choice D) is a fundamental particle, not an antiparticle. Therefore, the correct answer is an antiproton (choice C), as it forms an antineutron when combined with an antineutrino.

2. The Gram stain is a differential staining technique used to classify bacteria based on their cell wall composition. Gram-positive bacteria appear

• A. Pink
• B. Blue
• C. Red
• D. Purple

Correct answer: D

Rationale: The Gram stain is a differential staining technique that categorizes bacteria into two groups based on their cell wall composition: Gram-positive and Gram-negative. Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which retains the crystal violet stain used in the Gram staining procedure. Consequently, Gram-positive bacteria appear purple under the microscope after staining. On the other hand, Gram-negative bacteria possess a thinner peptidoglycan layer and an outer membrane that can be penetrated by the counterstain safranin, leading them to appear pink or red. Blue is not typically used to describe the color of bacteria in a Gram stain, making it an incorrect choice.

3. How does AIDS impair the immune system?

• A. AIDS targets and destroys Helper T-Cells, preventing the activation of Cytotoxic T-Cells or B-Cells.
• B. IgE stimulates mast cells to release excessive histamine.
• C. IgE inhibits mast cells from releasing sufficient histamine.
• D. Helper T-Cells deceive the body into attacking itself.

Correct answer: A

Rationale: AIDS targets and destroys Helper T-Cells, which play a crucial role in coordinating the immune response. By affecting these cells, AIDS prevents the activation of other important immune cells like Cytotoxic T-Cells or B-Cells. This disruption in the immune system's communication and response mechanisms leads to immune system failure and increased vulnerability to infections. Choices B and C are incorrect because they refer to the role of IgE in allergic reactions, which is not directly related to how AIDS impairs the immune system. Choice D is also incorrect as Helper T-Cells being destroyed in AIDS is not about deceiving the body into attacking itself, but rather the direct impact on immune system function.

4. Which statement accurately defines power?

• A. Power is the amount of energy stored in an object
• B. Power is the rate at which energy is transferred or work is done
• C. Power is the maximum force exerted by an object
• D. Power is the resistance of an object to change in motion

Correct answer: B

Rationale: Power is defined as the rate at which energy is transferred or work is done. It is a measure of how quickly work is done or energy is transferred. Option A incorrectly refers to the amount of energy stored in an object, not power. Option C incorrectly refers to the maximum force exerted by an object, not power. Option D incorrectly refers to the resistance of an object to change in motion, not power. Therefore, the correct definition of power is that it is the rate at which energy is transferred or work is done.

5. Why are negative feedback mechanisms crucial in the endocrine system?

• A. To increase hormone production continuously
• B. To maintain hormone levels within a specific range
• C. To cause a constant release of hormones
• D. To disrupt communication between glands

Correct answer: B

Rationale: Negative feedback mechanisms in the endocrine system play a vital role in maintaining hormone levels within a specific range. When hormone levels deviate from the set point, negative feedback signals prompt adjustments in hormone production to bring the levels back to the optimal range. This process ensures a delicate balance of hormones in the body, preventing excesses or deficiencies. Choice A is incorrect because continuously increasing hormone production would lead to imbalances. Choice C is incorrect as a constant release of hormones without regulation would disrupt homeostasis. Choice D is incorrect because disrupting communication between glands would hinder proper coordination and regulation of hormone levels, which is essential for the body's overall function.

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