Nursing Elites

1. When is a solution considered saturated?

• A. More solute cannot be dissolved
• B. The solvent starts to evaporate
• C. The solution becomes cloudy
• D. It reaches a specific temperature

Correct answer: A

Rationale: A solution is considered saturated when it has dissolved the maximum amount of solute that can be dissolved at a given temperature. At this point, adding more solute will not result in further dissolution, indicating that the solution is saturated. The other choices are incorrect because the solvent evaporating or the solution becoming cloudy are not definitive indicators of a saturated solution. Additionally, reaching a specific temperature does not determine saturation, as the solubility of a solute can vary with temperature. Therefore, the correct answer is that more solute cannot be dissolved in a saturated solution.

2. In endocrine regulation, the feedback loop is a critical concept. In a negative feedback loop, high levels of a hormone can result in:

• A. Further stimulating the release of the same hormone
• B. Inhibiting the release of the hormone or its production
• C. Having no effect on the hormone's regulation
• D. Increasing the need for another hormone entirely

Correct answer: B

Rationale: In a negative feedback loop, high levels of a hormone will inhibit the release of the hormone or its production. This mechanism is crucial for maintaining homeostasis by preventing excessive levels of hormones in the body. When a hormone reaches a certain concentration, it triggers the body to decrease its production or release, thereby ensuring a balance within the system. Choice A is incorrect because a negative feedback loop aims to counteract high hormone levels, not further stimulate them. Choice C is incorrect as high hormone levels do have an effect by triggering the feedback loop. Choice D is incorrect as the negative feedback loop operates within the same hormone system rather than increasing the need for an entirely different hormone.

3. An atom has 2 protons, 4 neutrons, and 2 electrons. What is the approximate atomic mass of this atom?

• A. 2
• B. 4
• C. 6
• D. 8

Correct answer: D

Rationale: The atomic mass of an atom is the sum of the protons and neutrons in its nucleus. In this case, the atom has 2 protons and 4 neutrons, totaling 6 particles in the nucleus. Therefore, the approximate atomic mass of this atom is 6, making choice C incorrect. The number of electrons does not significantly contribute to the atomic mass, as they are much lighter and located in the electron cloud surrounding the nucleus. Choices A, B, and C are incorrect as they do not reflect the correct calculation of atomic mass based on protons and neutrons only.

4. In a study evaluating which type of road salt deices a road most quickly, what is the independent variable?

• A. Deicing time period
• B. Road used for deicing
• C. Type of road salt used
• D. Amount of road salt used

Correct answer: C

Rationale: The correct answer is C, 'Type of road salt used.' In an experiment, the independent variable is the one manipulated by the researcher to observe its impact on the dependent variable. In this study, the researchers are altering the type of road salt used to determine its influence on the deicing speed, thus making it the independent variable. The other choices are not the independent variable as they are not deliberately manipulated in the experiment: A - 'Deicing time period' is an outcome measure dependent on the type of salt used; B - 'Road used for deicing' is not controlled or manipulated; D - 'Amount of road salt used' would be a potential confounding variable rather than the independent variable as it could affect the outcome along with the type of salt.

5. Which of the following is best identified as a hypothesis?

• A. The environmental temperature can affect the growth of a plant's root.
• B. Plants need light to grow.
• C. A colder environment produces longer roots.
• D. Plants need 60 days to grow their roots.

Correct answer: A

Rationale: Choice A is the best example of a hypothesis as it presents a testable statement regarding the impact of environmental temperature on plant root growth. A hypothesis should be specific and capable of being tested through experimentation, which is demonstrated in choice A. Choice B is a general statement rather than a testable hypothesis. Choice C lacks specificity and does not clearly state a cause-and-effect relationship to be tested. Choice D provides a specific time frame but does not address a relationship that can be tested through experimentation, making it less suitable as a hypothesis compared to choice A.

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