Nursing Elites

1. Which of the following statements describes a chemical property of water?

• A. Water has a pH of 1.
• B. A water molecule contains 2 hydrogen atoms and 1 oxygen atom.
• C. A water molecule contains 2 oxygen atoms and 1 hydrogen atom.
• D. The chemical formula for water is HO.

Correct answer: B

Rationale: The correct answer is B because a water molecule consists of two hydrogen atoms and one oxygen atom, which is a fundamental chemical property of water. The pH of water is not a property of the water molecule itself but rather a measure of its acidity or alkalinity. Choice C is incorrect as it describes a different molecule, not water. Choice D provides an incorrect chemical formula for water, which is H2O.

2. If a biochemist isolates a large amount of pyruvate, which part of the cell is he working with?

• A. Chloroplasts
• B. Cytoplasm
• C. Mitochondria
• D. Nucleus

Correct answer: B

Rationale: The correct answer is B: Cytoplasm. Pyruvate is a product of glycolysis, a metabolic pathway that takes place in the cytoplasm of the cell. Therefore, a biochemist isolating a large amount of pyruvate would be working with the cytoplasm of the cell. Choice A, Chloroplasts, is incorrect because pyruvate is not produced in chloroplasts, which are responsible for photosynthesis. Choice C, Mitochondria, is incorrect as pyruvate is produced in the cytoplasm before entering the mitochondria for further metabolism. Choice D, Nucleus, is incorrect as the nucleus is not involved in the production or isolation of pyruvate, which is a metabolic intermediate.

3. What is the primary function of the atrioventricular (AV) node within the heart?

• A. Generate the electrical impulse for contraction (pacemaker function)
• B. Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction.
• C. Increase blood pressure within the ventricles during systole.
• D. Separate oxygenated and deoxygenated blood flow in the heart.

Correct answer: B

Rationale: The correct answer is B: Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction. The primary function of the atrioventricular (AV) node is to coordinate the transmission of electrical signals between the atria and the ventricles. It ensures proper timing between atrial and ventricular contractions, allowing for efficient blood pumping through the heart. Choice A is incorrect because the AV node does not generate the initial electrical impulse; that role is typically attributed to the sinoatrial (SA) node. Choice C is incorrect as the AV node does not directly influence blood pressure within the ventricles. Choice D is also incorrect as the separation of oxygenated and deoxygenated blood is primarily achieved by the anatomical structure of the heart (e.g., atria and ventricles) and not the AV node.

4. What is surgically altered during a vasectomy?

• A. Vas deferens
• B. Glans penis
• C. Prostate
• D. Urethra

Correct answer: A

Rationale: During a vasectomy, the vas deferens is surgically altered or cut to prevent the transport of sperm from the testicles to the urethra. This procedure is a form of permanent male sterilization. The glans penis, prostate, and urethra are not surgically altered during a vasectomy. Therefore, the correct answer is the vas deferens (Choice A), as it is the structure specifically targeted and modified in this procedure. The glans penis (Choice B) is the sensitive tip of the penis, the prostate (Choice C) is a gland vital for semen production but not involved in a vasectomy, and the urethra (Choice D) is the tube that carries urine and semen but is not surgically altered in a vasectomy.

5. Which phenomenon describes the separation of light into its component colors when passing through a prism?

• A. Refraction
• B. Diffraction
• C. Dispersion
• D. Reflection

Correct answer: C

Rationale: Dispersion is the phenomenon that describes the separation of light into its component colors when passing through a prism. When white light enters a prism, it is refracted at different angles depending on its wavelength, causing the colors to spread out. Refraction is the bending of light as it passes from one medium to another, not the separation of colors. Diffraction is the bending of light around obstacles, not the separation of colors. Reflection is the bouncing back of light rays from a surface, not the separation of colors. In the context of a prism, dispersion plays a key role in the creation of a spectrum of colors by separating the different wavelengths present in white light.

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