Nursing Elites

1. Which of the following is the smallest unit of matter?

• A. Molecule
• B. Atom
• C. Compound
• D. Element

Correct answer: B

Rationale: An atom is the fundamental building block of matter, while molecules are formed by the combination of atoms.

2. Which of the following is the region of the brain that controls and regulates autonomic functions such as respiration, digestion, and heart rate?

• A. cerebellum
• B. medulla oblongata
• C. temporal lobe
• D. cerebral cortex

Correct answer: B

Rationale: The medulla oblongata is the correct answer. It is the region of the brain located at the base of the brainstem responsible for regulating autonomic functions such as respiration, digestion, and heart rate. These functions are essential for maintaining life. The cerebellum (Option A), temporal lobe (Option C), and cerebral cortex (Option D) do not control these autonomic functions. The cerebellum is mainly involved in coordination and balance, the temporal lobe is associated with memory and hearing, and the cerebral cortex is responsible for higher brain functions like thinking and decision-making.

3. What type of genetic variation is caused by changes in the DNA sequence?

• A. Epigenetic variation
• B. Phenotypic variation
• C. Genotypic variation
• D. Behavioral variation

Correct answer: C

Rationale: A) Epigenetic variation refers to changes in gene expression that do not involve alterations in the DNA sequence itself. These changes can be influenced by environmental factors. B) Phenotypic variation refers to differences in observable traits or characteristics of an organism, which can be influenced by both genetic and environmental factors. C) Genotypic variation is caused by changes in the DNA sequence, such as mutations or genetic recombination. These changes directly impact the genetic information carried by an organism. D) Behavioral variation refers to differences in behavior among individuals of the same species, which can be influenced by genetic, environmental, and experiential factors.

4. What happens during expiration?

• A. The diaphragm contracts and the thoracic cavity expands.
• B. The diaphragm relaxes and the thoracic cavity contracts.
• C. The thoracic cavity expands, increasing pressure.
• D. The diaphragm relaxes and moves upward.

Correct answer: B

Rationale: The correct answer is B. During expiration, the diaphragm relaxes, causing the thoracic cavity to contract. As the thoracic cavity decreases in size, the pressure inside the lungs increases, leading to air flowing out of the lungs. This process helps to expel carbon dioxide-rich air from the body. Choices A, C, and D are incorrect. In choice A, the diaphragm contracting and the thoracic cavity expanding describes inspiration, not expiration. Choice C is incorrect because during expiration, the thoracic cavity actually decreases in size. Choice D is incorrect as the diaphragm moving upward is not a typical movement associated with expiration.

5. 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.

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