Nursing Elites

1. Why does ice have the capability of floating on water?

• A. It has a higher viscosity
• B. It has a different chemical composition
• C. It has a high specific heat
• D. It forms a lattice when freezing

Correct answer: D

Rationale: The correct answer is D. Ice forms a lattice structure when it freezes, which makes it less dense than liquid water, allowing it to float. Choice A is incorrect because viscosity refers to a fluid's resistance to flow and is not related to ice floating. Choice B is incorrect as ice and liquid water have the same chemical composition (H2O). Choice C is incorrect because the high specific heat of water is not the reason why ice floats.

2. Which of the following statements is true if a molecule exhibits adhesion?

• A. Two molecules of the same substance have the ability to stay bonded to one another
• B. The molecule has the ability to bond to or attract other molecules
• C. A molecule has the ability to increase its heat when necessary
• D. The molecule has the ability to form hydrogen bonds

Correct answer: B

Rationale: The correct statement is that if a molecule exhibits adhesion, it has the ability to bond to or attract other molecules. Adhesion refers to the ability of a molecule to bind to or attract different types of molecules. Choice A is incorrect because adhesion is about bonding to different molecules, not the same substance. Choice C is incorrect as adhesion does not relate to the ability of a molecule to increase its heat. Choice D is incorrect because forming hydrogen bonds is a specific type of interaction and not a general characteristic of molecules exhibiting adhesion.

3. 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.

4. What is the most significant contributor to cellular function?

• A. Proteins
• B. Phospholipids
• C. Carbohydrates
• D. Fatty acids

Correct answer: A

Rationale: The correct answer is A: Proteins. Proteins are the most significant contributor to cellular function as they play crucial roles in almost all biological processes. They act as enzymes that catalyze reactions, are involved in cell signaling pathways, and provide structural support to cells. Phospholipids (Choice B), while important for cell membrane structure, do not have the same diverse functions as proteins in cellular processes. Carbohydrates (Choice C) primarily serve as an energy source and structural components but are not as versatile in cellular functions as proteins. Fatty acids (Choice D) are essential components of cell membranes and energy storage molecules but do not have the same broad range of functions as proteins in cellular processes.

5. What are the nitrogenous bases of DNA?

• A. Adenine, cytosine, guanine, and thymine
• B. Adenine, guanine, and uracil
• C. Adenine, guanine, and thymine
• D. Adenine, cytosine, guanine, and uracil

Correct answer: A

Rationale: The correct answer is A: Adenine, cytosine, guanine, and thymine. These are the four nitrogenous bases found in DNA. Adenine pairs with thymine, and cytosine pairs with guanine, forming the complementary base pairs in the double helix structure of DNA. Choice B is incorrect because uracil is a nitrogenous base found in RNA, not DNA. Choice C is incorrect as it is missing cytosine, one of the four bases in DNA. Choice D is incorrect because uracil is not a nitrogenous base in DNA, and it also lacks thymine, which is essential for DNA structure.

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