Nursing Elites

1. In an oxidation reaction,

• A. an oxidizing agent gains electrons.
• B. an oxidizing agent loses electrons.
• C. a reducing agent gains electrons.
• D. a reducing agent loses electrons.

Correct answer: B

Rationale: In an oxidation reaction, the substance being oxidized loses electrons, not gains them. An oxidizing agent is responsible for causing oxidation in another substance by accepting electrons, hence it undergoes reduction and loses electrons. Therefore, the correct statement is 'an oxidizing agent loses electrons,' making choice B the correct answer. Choices A, C, and D are incorrect because in an oxidation reaction, the oxidizing agent does not gain electrons, a reducing agent does not gain electrons, and a reducing agent does not lose electrons.

2. How does electron configuration relate to the periodic table?

• A. Elements within the same period have identical electron configurations.
• B. Elements within the same group share similar electron configurations in their outermost shell.
• C. Electron configuration determines an element's position on the periodic table.
• D. An element's group on the periodic table is determined by the number of electron shells it possesses.

Correct answer: B

Rationale: Elements within the same group share similar electron configurations in their outermost shell. The periodic table is organized based on the number of electrons in the outermost energy level, known as valence electrons, which significantly influence an element's chemical properties. Elements within the same group have the same number of valence electrons, leading to comparable chemical behaviors. Choices A and D are incorrect because elements within the same period, not group, have identical electron configurations, and an element's group is primarily determined by the number of valence electrons and not the number of electron shells. Choice C is incorrect because while electron configuration is crucial for understanding an element's properties, it is not the sole factor determining its position on the periodic table.

3. When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

• A. Negative feedback.
• B. Positive feedback.
• C. Stress response.
• D. Parasympathetic regulation.

Correct answer: A

Rationale: This mechanism is an example of negative feedback. Negative feedback systems work to counteract changes in the body and maintain a stable internal environment (homeostasis). In this case, the release of insulin in response to high glucose levels is followed by a reduction in insulin release when glucose levels drop. This response helps regulate glucose levels and return them to a normal range, demonstrating the characteristic of negative feedback where the body's response opposes the initial stimulus to maintain equilibrium. Positive feedback would amplify the initial change rather than counteract it, so it is not the correct choice. Stress response and parasympathetic regulation are not directly involved in this glucose regulation process, making them incorrect choices.

4. What is the most common cause of aseptic meningitis?

• A. Bacteria
• B. Viruses
• C. Fungi
• D. Parasites

Correct answer: B

Rationale: Aseptic meningitis is typically caused by viral infections, such as enteroviruses (e.g., coxsackievirus, echovirus), herpes simplex virus, varicella-zoster virus, and others. These viruses can infect the meninges, leading to inflammation and symptoms of meningitis without the presence of bacteria. While bacterial meningitis is a serious and life-threatening condition, aseptic meningitis caused by viruses is usually less severe and has a better prognosis. Fungi and parasites are less common causes of meningitis compared to bacteria and viruses.

5. Which of the following describes the difference between prokaryotic and eukaryotic cells?

• A. Prokaryotic cells have a nucleus, while eukaryotic cells don't.
• B. Eukaryotic cells are simpler in structure than prokaryotic cells.
• C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells don't.
• D. Eukaryotic cells have a true nucleus and membrane-bound organelles, while prokaryotic cells lack these.

Correct answer: D

Rationale: Eukaryotic cells have a true nucleus that contains the genetic material, while prokaryotic cells lack a true nucleus. Eukaryotic cells also have membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus, which are absent in prokaryotic cells.

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