Nursing Elites

1. What is the net ionic equation for the reaction: 2HCl(aq) + Ba(OH)2(aq) → 2H2O(l) + BaCl2(aq)?

• A. 2H+(aq) + 2OH-(aq) → 2H2O(l)
• B. 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)
• C. 2H+(aq) + Ba2+(aq) → Ba2+(aq) + 2H+(aq)
• D. Ba(OH)2(aq) + HCl(aq) → BaCl2(aq) + 2H2O(l)

Correct answer: A

Rationale: In the given reaction, the complete ionic equation is: 2H+(aq) + 2Cl-(aq) + Ba2+(aq) + 2OH-(aq) → 2H2O(l) + Ba2+(aq) + 2Cl-(aq). Spectator ions (Ba2+ and Cl-) do not participate in the net ionic equation, which simplifies to: 2H+(aq) + 2OH-(aq) → 2H2O(l). This equation represents the significant species involved in the reaction, showcasing the formation of water from the combination of hydrogen ions and hydroxide ions, resulting in the production of water molecules.

2. What enzyme plays a key role in breaking down carbohydrates in the small intestine?

• A. Pepsin
• B. Lipase
• C. Amylase
• D. Trypsin

Correct answer: C

Rationale: Amylase is the enzyme responsible for breaking down carbohydrates in the small intestine. It specifically targets starches and sugars, breaking them down into smaller molecules like maltose and glucose that can be absorbed by the body. Pepsin is an enzyme that breaks down proteins in the stomach, not the small intestine. Lipase is responsible for breaking down fats, not carbohydrates. Trypsin is an enzyme that breaks down proteins in the small intestine, not carbohydrates.

3. Which of the following neurotransmitters slows down the activity of neurons to prevent overexcitation?

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

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA is an inhibitory neurotransmitter that slows down neuronal activity, helping to prevent overexcitation in the brain. It counterbalances the effects of excitatory neurotransmitters like glutamate, playing a crucial role in maintaining the balance of neuronal activity in the brain. Acetylcholine (Choice A) is primarily an excitatory neurotransmitter involved in muscle movement and cognitive functions. Dopamine (Choice B) plays a role in reward-motivated behavior and motor control. Serotonin (Choice D) is involved in regulating mood, appetite, and sleep but is not primarily responsible for slowing down neuronal activity to prevent overexcitation.

4. Which group of antibiotics targets the cell wall of bacteria?

• A. Penicillins
• B. Tetracyclines
• C. Macrolides
• D. Fluoroquinolones

Correct answer: A

Rationale: Penicillins are a group of antibiotics that target the bacterial cell wall by inhibiting the synthesis of peptidoglycan, a vital component of the cell wall. This inhibition weakens the cell wall, leading to bacterial cell lysis and death. Penicillins are particularly effective against Gram-positive bacteria due to their mechanism of action. Tetracyclines (B) inhibit protein synthesis, Macrolides (C) interfere with bacterial ribosomes, and Fluoroquinolones (D) target bacterial DNA gyrase and topoisomerase IV. Unlike Penicillins, these antibiotics do not directly target the cell wall of bacteria.

5. Which term best describes the gradual change in a species over time in response to environmental pressures?

• A. Punctuated equilibrium (rapid bursts of evolution)
• B. Gradualism (slow and continuous change)
• C. Founder effect (genetic drift in a small population)
• D. Adaptive radiation (rapid diversification of a species)

Correct answer: B

Rationale: A) Punctuated equilibrium refers to rapid bursts of evolution followed by long periods of stability, rather than gradual change over time in response to environmental pressures. B) Gradualism is the process by which species evolve through slow and continuous changes over time in response to environmental pressures. This gradual change can lead to the development of new traits and adaptations. C) Founder effect is a type of genetic drift that occurs when a small group of individuals establishes a new population, leading to a loss of genetic variation compared to the original population. It does not specifically describe the gradual change in a species over time. D) Adaptive radiation is the rapid diversification of a species into a variety of forms to exploit different ecological niches, but it does not specifically refer to the gradual change in response to environmental pressures. Therefore, the term that best describes the gradual change in a species over time in response to environmental pressures is 'Gradualism.'

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