Nursing Elites

1. An investigator wishes to test the effect of temperature on the durability of a certain material. He places five blocks of this material in a sunny area in a meadow and five more in a cold area high in the mountains. He then monitors them over time. What is the main problem with this experiment?

• A. Ten subjects are far too small a number to obtain effective results.
• B. It is impossible to control for the fact that the blocks in the mountains were placed later.
• C. There are too many variables that are not being controlled for.
• D. Nothing is wrong with this experiment; this demonstrates good experimental procedure.

Correct answer: C

Rationale: The main problem with this experiment is that there are too many variables that are not being controlled for. The investigator is only changing one variable (temperature) while there are other variables at play such as humidity, exposure to light, and potential differences in the material itself. Without controlling or accounting for these additional variables, it would be difficult to determine if any observed differences in durability are solely due to temperature. Choice A is incorrect because the issue is not solely about the number of subjects but about the lack of control over variables. Choice B is not the main problem as the order of placement may not significantly impact the results. Choice D is incorrect as the experiment lacks proper control over variables, which is a crucial aspect of good experimental procedure.

2. Which of the following best describes the function of the pericardium?

• A. Regulating blood flow through valves within the heart.
• B. Acting as a protective sac surrounding the heart.
• C. Generating the electrical impulses for heart contractions.
• D. Transmitting electrical signals between the atria and ventricles.

Correct answer: B

Rationale: The pericardium is a double-layered sac that surrounds and protects the heart. Its main functions include preventing overfilling of the heart, providing a physical barrier against infection and inflammation, and reducing friction between the heart and surrounding structures. Choices A, C, and D do not accurately describe the function of the pericardium. Option B is the correct answer as it aligns with the protective and supportive role of the pericardium, distinguishing it from the functions attributed to choices A, C, and D.

3. Melanin, the pigment responsible for skin color, is produced by

• A. Keratinocytes (These cells produce keratin)
• B. Melanocytes
• C. Sebocytes (These cells produce sebum)
• D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: Melanocytes are the cells responsible for producing melanin, the pigment that determines skin color. Melanin gives skin its color and protects it from the harmful effects of UV radiation. Keratinocytes produce keratin, a tough protein that forms the outer layer of the skin, hair, and nails. Sebocytes produce sebum, an oily substance that helps moisturize and protect the skin. Langerhans cells are a type of immune cell found in the skin that play a role in protecting against infections and foreign substances but do not produce melanin.

4. What is the term for a solution that contains less solute than the maximum amount it could dissolve at a specific temperature and pressure?

• A. Saturated solution
• B. Unsaturated solution
• C. Supersaturated solution
• D. Concentrated solution

Correct answer: B

Rationale: An unsaturated solution is a solution that contains less solute than the maximum amount it could dissolve at a specific temperature and pressure. In an unsaturated solution, more solute can still be added and dissolved in the solvent. Choice A, a saturated solution, refers to a solution in which the maximum amount of solute has been dissolved at a specific temperature and pressure, leading to equilibrium. Choice C, a supersaturated solution, contains more solute than it can normally hold at a specific temperature and pressure, achieved through special conditions followed by rapid cooling or evaporation. Choice D, a concentrated solution, refers to a solution with a high amount of solute compared to the amount of solvent, regardless of reaching the saturation point.

5. Which element's neutral atom has 2 electrons in the first shell and 6 electrons in the second shell of the electron cloud?

• A. Beryllium
• B. Carbon
• C. Helium
• D. Oxygen

Correct answer: D

Rationale: The correct answer is Oxygen. Oxygen has a total of 8 electrons, with 2 in the first shell and 6 in the second shell. This configuration matches the description provided in the question. Choice A, Beryllium, has 2 electrons in total, so it cannot have 2 in the first shell and 6 in the second. Choice B, Carbon, has 6 electrons in total, so it also does not match the given electron distribution. Choice C, Helium, has only 2 electrons in total and therefore does not fit the electron configuration described in the question.

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