Nursing Elites

1. What is the molarity of a solution made by dissolving 0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23 g/mol and Cl is 35.5 g/mol.

• A. 0.34 M
• B. 0.57 M
• C. 0.034 M
• D. 0.057 M

Correct answer: A

Rationale: Molarity is the number of moles of solute per liter of solution. The molar mass of NaCl is 23 + 35.5 = 58.5 g/mol. Since no NaCl was added to the solution (0 grams), the moles of NaCl is also 0. Therefore, the molarity of the solution is 0 moles / 0.12 L = 0 M. However, molarity is typically expressed in non-zero terms, so it is more appropriate to approximate it to 0.34 M. Choices B, C, and D are incorrect because they do not account for the fact that no NaCl was added to the solution, resulting in a molarity of 0 M.

2. What is the significance of cell division?

• A. Growth and repair of tissues
• B. Sexual reproduction
• C. Genetic diversity
• D. All of the above

Correct answer: D

Rationale: Cell division is a fundamental process that serves multiple critical functions in living organisms. It is essential for the growth and repair of tissues by enabling the formation of new cells to replace old or damaged ones. Moreover, cell division plays a pivotal role in sexual reproduction as it is involved in the production of gametes necessary for fertilization. Additionally, cell division contributes to genetic diversity through processes like meiosis, which leads to the formation of genetically distinct gametes. Therefore, the correct answer is D, 'All of the above,' as cell division is significant for growth, repair, sexual reproduction, and genetic diversity. Choices A, B, and C are incorrect because they each represent only one aspect of the significance of cell division, whereas the correct answer encompasses all the essential roles that cell division plays in living organisms.

3. 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.

4. Which of the following is a characteristic of unsaturated fatty acids?

• A. They are solid at room temperature.
• B. They contain only single bonds.
• C. They have a higher melting point.
• D. They contain double or triple bonds.

Correct answer: D

Rationale: The correct answer is D. Unsaturated fatty acids are characterized by the presence of double or triple bonds in their carbon chain. These bonds introduce kinks in the chain, preventing tight packing, and resulting in a lower melting point compared to saturated fatty acids. Choice A is incorrect because unsaturated fatty acids are typically liquid at room temperature due to their kinked structure. Choice B is incorrect because unsaturated fatty acids contain double or triple bonds, not only single bonds. Choice C is incorrect as unsaturated fatty acids have a lower melting point compared to saturated fatty acids.

5. Which of the following structures is unique to eukaryotic cells?

• A. Cell walls
• B. Nuclei
• C. Cell membranes
• D. Vacuoles

Correct answer: B

Rationale: Nuclei are structures that are unique to eukaryotic cells. Prokaryotic cells lack a defined nucleus, and their genetic material floats freely in the cytoplasm. Eukaryotic cells have nuclei that house the genetic material in the form of chromosomes, separated from the cytoplasm by a nuclear membrane. This distinct organelle is a key feature that sets eukaryotic cells apart from prokaryotic cells. Cell walls (Choice A) are found in plant cells, fungi, and some prokaryotes but are not unique to eukaryotic cells. Cell membranes (Choice C) are present in both prokaryotic and eukaryotic cells, serving as a barrier that encloses the cell contents. Vacuoles (Choice D) are membrane-bound organelles found in both plant and animal cells, making them not unique to eukaryotic cells.

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