Nursing Elites

1. Which human body system is correctly matched with its function?

• A. Respiratory system; exchanges oxygen and carbon dioxide in the lungs.
• B. Circulatory system; transports oxygen to cells and removes carbon dioxide.
• C. Lymphatic system; produces antibodies that destroy virally affected or foreign cells.
• D. Endocrine system; regulates hormones controlling bodily functions and metabolism.

Correct answer: B

Rationale: The circulatory system is responsible for the transportation of oxygen from the lungs to all the body's cells and tissues, as well as removing carbon dioxide from the cells and transporting it back to the lungs to be exhaled. This process is crucial for cellular respiration and the exchange of gases necessary for bodily functions. Choice B accurately matches the role of the circulatory system by describing its function of transporting oxygen to cells and removing carbon dioxide, which is essential for maintaining proper cellular activities. Choices A, C, and D are incorrect because they do not accurately match the body system with its function. The respiratory system primarily involves the exchange of gases in the lungs, not transportation to cells; the lymphatic system deals with immunity through the production of antibodies, not gas exchange; and the endocrine system's main function is hormone regulation, not the transport of gases.

2. In order to be included in the formation of a scientific conclusion, evidence must be:

• A. Quantitative
• B. Reproducible
• C. Obvious
• D. All of the above

Correct answer: B

Rationale: For scientific evidence to be included in the formation of a scientific conclusion, it must be reproducible. Reproducibility is a fundamental aspect of the scientific method, ensuring that the same experiment will yield the same results if repeated. This allows other researchers to verify the findings and conclusions drawn from the evidence, enhancing the reliability and validity of the scientific process. While quantitative data can be important in supporting evidence, it is not a strict requirement for evidence to be included in scientific conclusions. The term 'obvious' is subjective and does not necessarily guarantee the reliability or reproducibility of the evidence, making it an unreliable criterion for scientific conclusions. Therefore, choice B, reproducible, is the correct answer as it aligns with the fundamental principles of the scientific method, emphasizing the importance of replicating results for establishing reliable conclusions.

3. Which phenomenon describes the bending of light as it travels from one medium to another with differing densities?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Dispersion

Correct answer: B

Rationale: Refraction is the phenomenon that describes the bending of light as it travels from one medium to another with differing densities. This bending occurs due to the change in speed of light as it moves from one medium to another, causing the light rays to change direction. Reflection refers to the bouncing back of light when it hits a surface, diffraction is the bending of light around obstacles, and dispersion is the separation of light into its different colors. Therefore, in the context of light moving through different media, refraction accurately describes the observed bending phenomenon.

4. Which of the following best describes a chemical change?

• A. Melting ice to form water
• B. Dissolving sugar in water
• C. Burning wood to produce ash
• D. Crushing a can to reduce its size

Correct answer: C

Rationale: A chemical change involves a chemical reaction where new substances are formed. Burning wood to produce ash is an example of a chemical change because the wood undergoes a chemical reaction to form a new substance (ash). In this process, the chemical composition of wood changes to produce ash, which is a new substance. On the other hand, melting ice to form water, dissolving sugar in water, and crushing a can to reduce its size are examples of physical changes. In these instances, the substances may change their physical state or appearance but do not undergo a chemical reaction to form new substances. Therefore, choice C is the correct answer as it represents a chemical change, while choices A, B, and D represent physical changes.

5. Balance the following redox reaction in acidic solution: I⁻ (aq) + Cr₂O₇²⁻ (aq) -> I₂ (aq) + Cr³⁺ (aq). Identify the oxidizing agent and reducing agent.

• A. I⁻ is oxidized, Cr₂O₇²⁻ is reduced
• B. I⁻ is reduced, Cr₂O₇²⁻ is oxidized
• C. Both I⁻ and Cr₂O₇²⁻ are oxidized
• D. Both I⁻ and Cr₂O₇²⁻ are reduced

Correct answer: B

Rationale: In the given redox reaction, I⁻ is gaining electrons to form I₂, which means I⁻ is being reduced (undergoing reduction). On the other hand, Cr₂O₇²⁻ is losing electrons to form Cr³⁺, indicating that Cr₂O₇²⁻ is being oxidized (undergoing oxidation). Therefore, I⁻ is the reducing agent and Cr₂O₇²⁻ is the oxidizing agent. Choice A is incorrect because I⁻ is being reduced, not oxidized. Choice C is incorrect as both species cannot be oxidized in the same reaction. Choice D is incorrect as both species cannot be reduced in the same reaction.

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