Nursing Elites

1. Which statement confirms that the cell membrane is selectively permeable?

• A. Receptors are found on a cell's surface.
• B. Cells communicate with each other using cell signals.
• C. Environmental changes can cause a cell to expand or shrink.
• D. Sodium ions must travel through ion channels to enter the cell.

Correct answer: D

Rationale: The correct answer is D because selective permeability is demonstrated by the fact that specific ions, such as sodium, require ion channels to cross the cell membrane. This process allows the cell to control what substances can enter or exit, highlighting the selective nature of the cell membrane. Choices A, B, and C do not directly relate to the concept of selective permeability of the cell membrane. Receptors on a cell's surface (Choice A) are involved in cell signaling rather than selective permeability. Cell communication through signals (Choice B) and environmental changes affecting cell size (Choice C) are not directly related to the selective permeability of the cell membrane, which specifically refers to the regulation of substances passing through the membrane.

2. Which of the following indicates the body's draining of clear fluid throughout the body to protect it from infection?

• A. Pulmonary Loop
• B. Systemic Loop
• C. Lymphatic System
• D. Immune System

Correct answer: C

Rationale: The correct answer is C, the Lymphatic System. The lymphatic system is responsible for draining clear fluid, known as lymph, throughout the body to protect it from infection. The other choices are incorrect because the pulmonary loop specifically refers to circulation between the heart and lungs, the systemic loop refers to circulation between the heart and the rest of the body, and the immune system is responsible for fighting infections and diseases rather than draining clear fluid.

3. Which of the following is a common characteristic of alkynes?

• A. They have a triple bond between carbon atoms.
• B. They are saturated hydrocarbons.
• C. They contain only single bonds.
• D. They are aromatic compounds.

Correct answer: A

Rationale: The correct answer is A. Alkynes are hydrocarbons characterized by at least one triple bond between carbon atoms. This triple bond sets them apart from alkanes, which only have single bonds, and alkenes, which feature at least one double bond. The presence of a triple bond makes alkynes unsaturated hydrocarbons. Choice B is incorrect as alkynes are unsaturated hydrocarbons, not saturated. Choice C is incorrect because alkynes contain at least one triple bond, making them different from compounds with only single bonds. Choice D is incorrect because aromatic compounds have a distinct cyclic structure with resonance stabilization, a feature not shared by alkynes.

4. Which property of matter refers to the amount of space occupied by an object and is measured in cubic units?

• A. Mass
• B. Density
• C. Weight
• D. Volume

Correct answer: D

Rationale: Volume is the property of matter that refers to the amount of space occupied by an object. It is measured in cubic units, such as cubic meters or cubic centimeters. Mass, on the other hand, is the amount of matter in an object, weight is the force of gravity acting on an object, and density is the mass per unit volume of a substance. In this question, the key concept is the space occupied by an object, which directly relates to volume, making it the correct answer. Choices A, B, and C are incorrect as they do not specifically pertain to the amount of space occupied by an object.

5. Which structure of the nervous system carries an action potential in the direction of a synapse?

• A. Cell body
• B. Axon
• C. Neuron
• D. Myelin

Correct answer: B

Rationale: The correct answer is the axon. The axon is the elongated, threadlike part of a neuron that carries nerve impulses away from the cell body towards other neurons or target cells, such as muscles or glands, in the direction of a synapse. Action potentials travel along the axon as electrical signals to communicate with neighboring cells. The cell body (choice A) contains the nucleus and organelles but does not transmit action potentials. Neuron (choice C) is a broad term that includes the entire nerve cell, not a specific structure. Myelin (choice D) is a fatty substance that surrounds and insulates axons, aiding in the conduction of nerve impulses, but it does not directly carry the action potential towards a synapse.

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