Nursing Elites

1. Which of the following neurotransmitters slows down the activity of neurons, preventing them from becoming overexcited?

• A. Acetylcholine
• B. Dopamine
• C. GABA
• D. Serotonin

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA acts as an inhibitory neurotransmitter that reduces neuronal activity, thus preventing overexcitation. Acetylcholine (choice A) is involved in muscle control and cognitive function, but it is not primarily responsible for slowing down neuronal activity. Dopamine (choice B) plays a role in reward-motivated behavior and motor control, rather than inhibiting neuronal firing. Serotonin (choice D) is involved in mood regulation, sleep, and appetite but does not primarily slow down neuronal activity to prevent overexcitation.

2. What is the main function of the nervous system?

• A. To fight infection
• B. To control body movement and coordination
• C. To regulate metabolism
• D. To transport oxygen

Correct answer: B

Rationale: The main function of the nervous system is to control body movement and coordination by transmitting signals between different parts of the body. Choice A is incorrect because the immune system, not the nervous system, is primarily responsible for fighting infections. Choice C is incorrect as regulating metabolism is primarily handled by the endocrine system. Choice D is incorrect because the transportation of oxygen is mainly the function of the circulatory system, specifically the blood.

3. 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.

4. Which of the following is an example of a nonpolar solvent?

• A. Water
• B. Ethanol
• C. Acetone
• D. Hydrochloric acid

Correct answer: B

Rationale: - Water (option A) is a polar solvent due to its uneven distribution of charge, with the oxygen atom being partially negative and the hydrogen atoms being partially positive. - Ethanol (option B) is a nonpolar solvent because it has a symmetrical molecular structure that does not result in significant charge separation. - Acetone (option C) is a polar solvent as it contains a carbonyl group that results in a partial negative charge on the oxygen atom. - Hydrochloric acid (option D) is a polar solvent due to the presence of the highly electronegative chlorine atom, which results in a partial negative charge.

5. Which of the following describes the general function of cytokines in the immune system?

• A. They communicate between cells to instigate an immune response.
• B. They inhibit blood clotting during inflammation responses.
• C. They bind to specific pathogens to increase pathogen mass.
• D. They transport pathogens trapped in mucus to be destroyed in the stomach.

Correct answer: A

Rationale: The correct answer is A: 'They communicate between cells to instigate an immune response.' Cytokines are signaling molecules that act as messengers between cells in the immune system, playing a vital role in coordinating and regulating immune responses. They communicate with various immune cells to initiate appropriate responses against pathogens. Choice B is incorrect because cytokines do not inhibit blood clotting but rather regulate immune responses. Choice C is incorrect as cytokines do not bind to specific pathogens to increase their mass; instead, they regulate the immune response. Choice D is also incorrect because cytokines do not transport pathogens trapped in mucus to the stomach for destruction; they primarily function as signaling molecules within the immune system.

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