Nursing Elites

1. A substance is only considered acidic if it has a pH less than what?

• A. 12
• B. 9
• C. 7
• D. 4

Correct answer: C

Rationale: A substance is considered acidic if its pH is less than 7. pH values below 7 indicate acidity, while pH values above 7 indicate alkalinity or basicity. Substances with a pH less than 7 are categorized as acidic, not above it. Therefore, a substance is classified as acidic if its pH is less than 7, making choice C the correct answer. Choices A, B, and D are incorrect because a pH of 12, 9, and 4, respectively, are all above 7, and therefore not indicative of acidity.

2. Which neurotransmitter is involved in muscle movement?

• A. Dopamine
• B. Acetylcholine
• C. Serotonin
• D. GABA

Correct answer: B

Rationale: Acetylcholine is the neurotransmitter responsible for muscle movement. It is released from motor neurons at the neuromuscular junction and binds to receptors on muscle fibers, initiating muscle contraction. Dopamine, serotonin, and GABA serve different functions in the brain and body, such as regulating mood, sleep, and inhibitory signaling, respectively. Therefore, choices A, C, and D are incorrect in the context of muscle movement.

3. Lymph nodes, found along lymphatic vessels, are important for:

• A. Storing blood
• B. Producing antibodies
• C. Filtering lymph and trapping harmful substances
• D. All of the above

Correct answer: C

Rationale: Lymph nodes are essential for filtering lymph and trapping harmful substances. They are a vital part of the immune system as they remove pathogens and harmful substances from the lymph before it returns to the bloodstream. Lymph nodes do not store blood or produce antibodies, making choice C the correct answer. Choice A is incorrect because lymph nodes do not store blood; they primarily filter lymph. Choice B is incorrect as lymph nodes do not produce antibodies; that function is mainly carried out by specialized cells within the immune system. Choice D is incorrect as lymph nodes do not perform all the functions listed, making it an incorrect answer.

4. Which property of a substance refers to its ability to be stretched into thin wires?

• A. Conductivity
• B. Viscosity
• C. Ductility
• D. Malleability

Correct answer: C

Rationale: Ductility is the property of a substance that allows it to be stretched into thin wires without breaking. It is a crucial property for materials used in wire production. Conductivity refers to the ability of a substance to conduct electricity or heat, not to be stretched into wires. Viscosity is the measure of a fluid's resistance to flow, not its ability to be stretched. Malleability is the property of a substance that allows it to be hammered or rolled into thin sheets, not stretched into wires.

5. The above experimental design description is an example of which of the following types of experiments?

• A. field experiment
• B. natural experiment
• C. controlled experiment
• D. observational study

Correct answer: C

Rationale: The above experimental design description involves the manipulation of an independent variable (light exposure) to observe its effects on the dependent variable (plant growth) under controlled conditions. In a controlled experiment, researchers actively manipulate one or more variables while keeping all other variables constant to establish cause-and-effect relationships. Choice A, a field experiment, typically takes place in a real-world setting but still involves manipulation and control of variables. Choice B, a natural experiment, involves observing naturally occurring differences in variables without researcher intervention. Choice D, an observational study, does not involve manipulation of variables, making it different from the described experimental design.

Similar Questions