Nursing Elites

1. Which of the following immune cells are part of the innate immune response?

• A. B-cells
• B. Cytotoxic T-cells
• C. Natural Killer cells
• D. Antigen-Presenting Cells

Correct answer: C

Rationale: Natural Killer cells are a crucial component of the innate immune response. They play a significant role in defending against infected or cancerous cells through their ability to identify and kill abnormal cells. B-cells (Choice A) and Cytotoxic T-cells (Choice B) are part of the adaptive immune response, which involves a more specific and targeted response to pathogens. Antigen-Presenting Cells (Choice D) are also part of the adaptive immune response, where they present antigens to activate other immune cells.

2. Which type of blood vessel carries oxygenated blood away from the heart?

• A. Vein
• B. Artery
• C. Capillary
• D. Lymphatic vessel

Correct answer: B

Rationale: The correct answer is B. Arteries carry oxygenated blood away from the heart to the rest of the body, delivering nutrients and oxygen to the tissues. Veins, on the other hand, carry deoxygenated blood back to the heart. Capillaries are where the exchange of gases, nutrients, and waste products occurs between the blood and tissues. Lymphatic vessels are responsible for transporting lymph, which is a clear fluid containing white blood cells and waste products, and play a key role in the immune system.

3. In a chemical reaction, the total amount of:

• A. Matter remains the same
• B. Matter increases
• C. Matter decreases
• D. Energy remains the same

Correct answer: A

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, only rearranged. This principle implies that the total amount of matter before and after a chemical reaction must remain constant, supporting the correct answer choice A. Choice B is incorrect because the total amount of matter does not increase in a chemical reaction; it is conserved. Choice C is incorrect as the total amount of matter does not decrease in a chemical reaction; it is conserved. Choice D is incorrect since the conservation of energy is a different principle and does not directly relate to the total amount of matter in a chemical reaction.

4. What happens to the density of a gas when its temperature increases at constant pressure?

• A. It increases.
• B. It decreases.
• C. It remains the same.
• D. Information is insufficient.

Correct answer: B

Rationale: When the temperature of a gas increases at constant pressure, the average kinetic energy of the gas molecules increases. This leads to the gas molecules moving faster and spreading out more, which causes them to occupy a larger volume. As a result, the density of the gas decreases because the same number of gas molecules are now distributed over a larger space. Choice A is incorrect because as the gas molecules spread out, the density decreases. Choice C is incorrect because the increase in temperature leads to a decrease in density due to the increased volume occupied by the gas molecules. Choice D is incorrect because with the provided scenario of temperature increase at constant pressure, the effect on density can be determined.

5. What happens when an atom loses an electron?

• A. It forms a molecule.
• B. It gains a positive charge and becomes an ion.
• C. It alters its elemental identity.
• D. No change occurs; it remains neutral.

Correct answer: B

Rationale: When an atom loses an electron, it gains a positive charge and becomes an ion. This occurs because the number of protons in the atom exceeds the number of electrons, leading to a positive charge. Therefore, the atom undergoes a transformation into an ion by losing an electron. Choice A is incorrect because losing an electron does not result in the formation of a molecule, as molecules are made up of bonded atoms. Choice C is incorrect because losing an electron does not change the fundamental identity of the atom; it only changes its charge. Choice D is incorrect because losing an electron causes the atom to become positively charged, altering its neutrality.

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