Nursing Elites

1. Which of the following molecules acts as the genetic code's messenger?

• A. RNA
• B. Proteins
• C. DNA
• D. Carbohydrates

Correct answer: A

Rationale: The correct answer is RNA. RNA, particularly mRNA, serves as the messenger that carries genetic information from DNA to the ribosome, where proteins are synthesized. Proteins (choice B) are not the genetic code's messenger; they are synthesized based on the information carried by RNA. DNA (choice C) stores the genetic information but does not directly act as the messenger. Carbohydrates (choice D) are not involved in transmitting genetic information.

2. Which organelle is responsible for the synthesis of lipids and steroid hormones?

• A. Rough endoplasmic reticulum
• B. Smooth endoplasmic reticulum
• C. Golgi apparatus
• D. Ribosomes

Correct answer: B

Rationale: The smooth endoplasmic reticulum is the correct organelle responsible for the synthesis of lipids, including phospholipids, cholesterol, and steroid hormones. The rough endoplasmic reticulum is primarily involved in protein synthesis and processing, making choice A incorrect. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids for transportation, so it is not directly involved in lipid and steroid hormone synthesis, making choice C incorrect. Ribosomes are responsible for protein synthesis and are not involved in lipid or steroid hormone synthesis, making choice D incorrect.

3. The liver is an organ responsible for detoxifying the body of many harmful substances. You might expect the liver to contain a high amount of which of the following?

• A. Rough endoplasmic reticulum
• B. Smooth endoplasmic reticulum
• C. Mitochondria
• D. Lysosomes

Correct answer: B

Rationale: The correct answer is B: Smooth endoplasmic reticulum. The liver contains a high amount of smooth endoplasmic reticulum because it plays a significant role in detoxification processes, such as the synthesis of detoxifying enzymes and lipids. Choice A (Rough endoplasmic reticulum) is incorrect because the rough endoplasmic reticulum is more involved in protein synthesis and processing. Choice C (Mitochondria) is incorrect as mitochondria are primarily responsible for energy production. Choice D (Lysosomes) is incorrect because lysosomes are organelles involved in intracellular digestion and waste removal, not specifically related to detoxification.

4. The cellular membrane contributes to all except which of the following?

• A. Cell energy production
• B. Cell permeability
• C. Cell communication
• D. Cell protection

Correct answer: A

Rationale: The cellular membrane is involved in regulating cell permeability, communication, and protection. However, it is not directly involved in energy production. Choice A is the correct answer because the cellular membrane does not produce energy; instead, it regulates the passage of molecules in and out of the cell. Choices B, C, and D are incorrect because the cell membrane plays key roles in controlling what enters and exits the cell, facilitating communication between cells, and providing structural support and protection to the cell.

5. Which of the following provides support and shape to the cell?

• A. Microtubules
• B. Microfilaments
• C. Cilia
• D. Microvilli

Correct answer: A

Rationale: Microtubules are fundamental components of the cytoskeleton in a cell, playing a crucial role in providing structural support and maintaining the cell's shape. They are composed of tubulin protein subunits and are involved in various cellular processes like cell division, intracellular transport, and cell motility. Microfilaments, on the other hand, are involved in cell movement and maintaining cell shape but are not primarily responsible for supporting the cell's overall structure. Cilia and microvilli are cellular projections that aid in movement and absorption, respectively, but they do not play a significant role in providing structural support to the cell.

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