Nursing Elites

1. Water is considered a universal solvent due to its ____.

• A. Cohesion
• B. Adhesion
• C. Molarity
• D. Dilution

Correct answer: B

Rationale: The correct answer is B: Adhesion. Water's polarity allows it to dissolve many substances due to its ability to adhere to and interact with other molecules, making it an effective solvent. Cohesion refers to water molecules sticking together, molarity is a measure of concentration, and dilution refers to the process of reducing the concentration of a solute in a solution, none of which directly relate to water's role as a universal solvent.

2. What element is responsible for the red color of blood?

• A. Magnesium
• B. Iron
• C. Copper
• D. Zinc

Correct answer: B

Rationale: The correct answer is B: Iron. Hemoglobin, the protein responsible for carrying oxygen in red blood cells, contains iron in its heme group, contributing to the blood's characteristic red color. Magnesium (choice A), copper (choice C), and zinc (choice D) are not responsible for the red color of blood. Magnesium is an essential mineral involved in various physiological processes, copper is a trace element important for enzyme function, and zinc is a micronutrient essential for multiple cellular functions but not related to the red color of blood.

3. What is the process by which the body reabsorbs water from the large intestine?

• A. Dehydration
• B. Osmosis
• C. Filtration
• D. Secretion

Correct answer: B

Rationale: Osmosis (Option B) is the correct process by which the body reabsorbs water from the large intestine. Osmosis is the movement of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. In the large intestine, water is reabsorbed through osmosis to maintain the body's fluid balance. Dehydration (Option A) refers to the condition of having insufficient water in the body, not the process of water reabsorption in the large intestine. Filtration (Option C) is a process where a liquid or gas passes through a filter to separate the components, not the primary mechanism for water reabsorption in the large intestine. Secretion (Option D) is the release of substances from cells, but it is not the process by which the body reabsorbs water from the large intestine.

4. What are the tiny contractile units within muscle cells called?

• A. Myocytes
• B. Myofibrils
• C. Sarcomeres
• D. Tendons

Correct answer: C

Rationale: Sarcomeres are the smallest contractile units within muscle cells. They consist of overlapping filaments of actin and myosin proteins, which interact to produce muscle contractions. Myocytes are the entire muscle cells, myofibrils are bundles of protein filaments found within muscle cells, and tendons are tough connective tissues that connect muscles to bones. Therefore, sarcomeres specifically represent the contractile units responsible for muscle contraction, making them the correct answer in this context.

5. Which macromolecules are composed of nucleotides and store information and energy?

• A. Lipids
• B. Proteins
• C. Carbohydrates
• D. Nucleic acids

Correct answer: D

Rationale: The correct answer is D: Nucleic acids. Nucleic acids, such as DNA and RNA, are composed of nucleotides and are responsible for storing genetic information and energy (e.g., ATP). Lipids, proteins, and carbohydrates are distinct macromolecules with varying functions and structures. Lipids primarily serve as energy reservoirs, structural components, and cell signaling molecules. Proteins play crucial roles in cellular functions like enzyme activity, structural support, and intracellular signaling. Carbohydrates are mainly utilized as an energy source and for structural purposes within cells.

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