Nursing Elites

1. Which of the following organs does not belong with the others?

• A. Thyroid gland
• B. Stomach
• C. Intestines
• D. Pancreas

Correct answer: B

Rationale: The correct answer is B - Stomach. The stomach is primarily involved in the digestive system, breaking down food through digestion. In contrast, the thyroid gland, intestines, and pancreas are part of the endocrine system or digestive system, involved in hormone production, nutrient absorption, and digestion. Therefore, the stomach stands out as the odd one in this group as it is the only organ specifically dedicated to digestion, while the others have dual roles or different primary functions.

2. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: Schwann cells are indeed responsible for producing the myelin sheath in the peripheral nervous system. These cells wrap around axons to form the myelin sheath, which enhances the speed of nerve impulse conduction. In the central nervous system, oligodendrocytes are responsible for producing the myelin sheath. Astrocytes provide support and maintenance functions for neurons, while neurons are the nerve cells themselves and do not produce myelin. Therefore, the correct answer is Schwann cells as they are specifically involved in myelin production in the peripheral nervous system.

3. What is the main function of peroxisomes in the cell?

• A. To break down hydrogen peroxide
• B. To synthesize lipids and other cellular components
• C. To package and transport proteins
• D. To store genetic material

Correct answer: A

Rationale: Peroxisomes are membrane-bound organelles found in eukaryotic cells that contain enzymes involved in various metabolic processes. One of the main functions of peroxisomes is to break down hydrogen peroxide, a toxic byproduct of metabolism, into water and oxygen through the action of the enzyme catalase. This process helps protect the cell from oxidative damage caused by hydrogen peroxide. While peroxisomes are involved in other metabolic functions such as lipid metabolism and the synthesis of bile acids, their primary role is the breakdown of hydrogen peroxide. Choices B, C, and D are incorrect because peroxisomes are not primarily responsible for synthesizing lipids, packaging and transporting proteins, or storing genetic material within the cell.

4. What is the term for the balanced equation that represents a chemical reaction?

• A. Hypothesis
• B. Chemical formula
• C. Balanced equation
• D. Reaction mechanism

Correct answer: C

Rationale: The correct answer is C - 'Balanced equation'. A balanced equation is a representation of a chemical reaction that shows the reactants, products, and their stoichiometric coefficients. It ensures that the number of atoms of each element is equal on both sides of the equation, following the law of conservation of mass. Choice A, 'Hypothesis', is incorrect as it refers to a proposed explanation based on limited evidence as a starting point for further investigation. Choice B, 'Chemical formula', is incorrect as it represents the composition of a compound using symbols and subscripts. Choice D, 'Reaction mechanism', is incorrect as it describes the step-by-step process by which a chemical reaction occurs, not just the overall representation of the reaction itself.

5. What unit is used for measuring luminous flux, which indicates the perceived brightness of a light source by the human eye?

• A. Candela
• B. Lumen
• C. Lux
• D. Hertz

Correct answer: B

Rationale: Lumen is the correct unit for measuring luminous flux, which quantifies the total visible light emitted by a source per unit of time. Candela measures luminous intensity, lux measures illuminance, and Hertz measures frequency. Therefore, in the context of measuring the perceived brightness of a light source by the human eye, luminous flux is quantified in lumens.

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