Nursing Elites

1. How is power defined in terms of physics?

• A. The rate at which work is done
• B. The amount of force applied
• C. The distance an object travels
• D. The potential energy of an object

Correct answer: A

Rationale: In physics, power is defined as the rate at which work is done, which refers to the amount of energy transferred or converted per unit time. Choice B, 'The amount of force applied,' is incorrect as power is related to work done, not just force. Choice C, 'The distance an object travels,' is not the definition of power but rather relates to displacement or distance. Choice D, 'The potential energy of an object,' is not the correct definition of power; potential energy is different from power. Therefore, the correct definition of power in physics is the rate at which work is done.

2. Which process allows for the movement of large molecules, such as proteins and polysaccharides, across the cell membrane?

• A. Endocytosis
• B. Exocytosis
• C. Active transport
• D. Facilitated diffusion

Correct answer: A

Rationale: Endocytosis is the process by which cells engulf large molecules or particles by wrapping the cell membrane around them to form a vesicle that is brought into the cell. This mechanism facilitates the movement of large molecules like proteins and polysaccharides across the cell membrane. Exocytosis involves the release of large molecules or particles from the cell, opposite to the scenario described in the question. Active transport requires energy to move molecules against their concentration gradient and is not primarily used for transporting proteins and polysaccharides. Facilitated diffusion entails the movement of molecules aided by transport proteins but is not the primary mechanism for transporting large molecules such as proteins and polysaccharides.

3. What is the role of hemoglobin in the human body?

• A. Transport oxygen in red blood cells
• B. Bind oxygen to red blood cells
• C. Carry carbon dioxide from tissues to lungs
• D. Help red blood cells transport oxygen

Correct answer: D

Rationale: The correct answer is D: 'Help red blood cells transport oxygen.' Hemoglobin acts as a carrier molecule in red blood cells, binding to oxygen in the lungs and releasing it in the tissues. It facilitates the transport of oxygen from the lungs to the tissues and aids in returning carbon dioxide from the tissues to the lungs. Choices A, B, and C are incorrect because hemoglobin itself does not transport oxygen independently or bind oxygen to red blood cells nor does it carry carbon dioxide from tissues to lungs; instead, it assists red blood cells in the transportation of oxygen.

4. Which of the following is an example of a chemical property of matter?

• A. Boiling point
• B. Flammability
• C. Density
• D. Conductivity

Correct answer: B

Rationale: Flammability is an example of a chemical property of matter because it describes how a substance reacts with oxygen in the air to produce heat and light. Chemical properties involve the ability of a substance to undergo a chemical change or reaction, such as burning. Boiling point, density, and conductivity are examples of physical properties, not chemical properties. Boiling point is the temperature at which a substance changes from a liquid to a gas, density is the mass of a substance per unit volume, and conductivity is the ability to conduct electricity. Therefore, flammability best exemplifies a chemical property as it pertains to the substance's reaction with oxygen, while the other options are physical properties that describe characteristics without changing the substance's chemical composition.

5. Which of the following nucleobases does not exist in RNA?

• A. Uracil
• B. Thymine
• C. Cytosine
• D. Guanine

Correct answer: B

Rationale: The correct answer is 'B: Thymine'. Thymine is a nucleobase found in DNA but is replaced by uracil in RNA. RNA contains Uracil, Cytosine, and Guanine as its nucleobases. Cytosine and Guanine are present in both DNA and RNA, while Thymine is exclusive to DNA and Uracil is specific to RNA.

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