Nursing Elites

1. The resolution of an optical instrument, like a microscope, refers to its ability to distinguish between:

• A. Different colors of light
• B. The presence or absence of light
• C. Variations in intensity
• D. Very close, nearly identical objects

Correct answer: D

Rationale: The resolution of an optical instrument, such as a microscope, refers to its ability to distinguish between very close, nearly identical objects. This is crucial in microscopy to clearly visualize and differentiate fine details and structures. Resolving power plays a significant role in determining the quality and effectiveness of an optical instrument. Choices A, B, and C are incorrect because the resolution of an optical instrument does not primarily deal with different colors of light, presence or absence of light, or variations in intensity. Instead, it specifically focuses on the instrument's ability to differentiate between objects that are very close and nearly identical in nature.

2. What is the formula for calculating molarity?

• A. M = n/V
• B. M = n/L
• C. M = mol/L
• D. M = mol/dm³

Correct answer: A

Rationale: The correct formula for calculating molarity is M = n/V. In this formula, 'M' represents molarity, 'n' represents the number of moles of solute, and 'V' represents the volume of the solution in liters. Molarity is defined as the number of moles of solute per liter of solution, hence the ratio of moles to volume. Choice B, 'M = n/L', is incorrect because 'L' should represent liters instead of the number of moles. Choice C, 'M = mol/L', is incorrect as it does not include the representation of the number of moles 'n'. Choice D, 'M = mol/dm³', is incorrect because 'dm³' is a volume unit equal to a liter, but the correct representation should be in terms of the volume of the solution in liters. Therefore, the correct answer is M = n/V.

3. What protein complex controls the progression of mitosis through its activation and degradation?

• A. Ribosome
• B. Cyclin-dependent kinase (CDK)
• C. Centriole
• D. Microtubule

Correct answer: B

Rationale: A) Ribosome: Ribosomes are cellular organelles responsible for protein synthesis and are not directly involved in controlling the progression of mitosis. B) Cyclin-dependent kinase (CDK): CDKs are a family of protein kinases that regulate the cell cycle, including the progression of mitosis. CDK activity is controlled by cyclins, which bind to CDKs to activate them at specific points in the cell cycle. The activation and degradation of cyclins regulate the activity of CDKs, which in turn control the progression of mitosis. C) Centriole: Centrioles are involved in organizing the microtubules of the mitotic spindle but do not directly control the progression of mitosis. D) Microtubule: Microtubules are structural components of the cytoskeleton and are involved in various cellular processes, including mitosis, but they do not control

4. How many neutrons and electrons could a negative ion of sulfur have?

• A. 16 neutrons, 16 electrons
• B. 16 neutrons, 17 electrons
• C. 17 neutrons, 16 electrons
• D. 17 neutrons, 17 electrons

Correct answer: B

Rationale: A negative ion of sulfur would have 16 protons and 17 electrons since it gains one electron. The number of neutrons in an ion does not change, so the neutrons would remain at 16. Therefore, the correct answer is 16 neutrons and 17 electrons, which corresponds to choice B. Choice A is incorrect as it does not account for the extra electron gained by the negative ion. Choices C and D are incorrect because they propose a change in the number of neutrons, which is not affected by the ionization process.

5. Which of the following is an example of a chemical property of matter?

• A. Boiling point
• B. Flammability
• C. Density
• D. Conductivity

Correct answer: B

Rationale: Flammability is an example of a chemical property of matter because it describes how a substance reacts with oxygen in the air to produce heat and light. Chemical properties involve the ability of a substance to undergo a chemical change or reaction, such as burning. Boiling point, density, and conductivity are examples of physical properties, not chemical properties. Boiling point is the temperature at which a substance changes from a liquid to a gas, density is the mass of a substance per unit volume, and conductivity is the ability to conduct electricity. Therefore, flammability best exemplifies a chemical property as it pertains to the substance's reaction with oxygen, while the other options are physical properties that describe characteristics without changing the substance's chemical composition.

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