Nursing Elites

1. How many neurons typically comprise a sensory pathway?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: C

Rationale: A sensory pathway generally consists of three neurons: a first-order neuron, a second-order neuron, and a third-order neuron. The first-order neuron carries sensory information from the periphery to the spinal cord or brainstem. The second-order neuron then transmits this information to the thalamus or cerebellum. Finally, the third-order neuron projects the sensory input to the cerebral cortex for processing and perception. Therefore, the correct answer is 3 (C). Choices A, B, and D are incorrect as they do not align with the typical structure of a sensory pathway involving three neurons.

2. Where is keratin found?

• A. It is a protein-digesting enzyme released by the stomach.
• B. It is released in the neuromuscular junction.
• C. It is a protein found in the hypodermis.
• D. It is a protein found in hair.

Correct answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

3. Which element has the lowest electronegativity value?

• A. Oxygen
• B. Fluorine
• C. Helium
• D. Chlorine

Correct answer: C

Rationale: The correct answer is Helium (C). Electronegativity is the tendency of an atom to attract electrons towards itself in a bond. Helium, as a noble gas, has a very low electronegativity because its outer electron shell is already full and stable, resulting in minimal attraction for additional electrons. Oxygen (A), Fluorine (B), and Chlorine (D) are all non-noble gas elements that have higher electronegativity values compared to Helium due to their electron configurations and tendencies to attract electrons.

4. DNA has both a 'sense' and 'antisense' strand. What is true about the antisense strand?

• A. It runs 5' to 3'.
• B. It runs 3' to 5'.
• C. It is used in replication.
• D. It is the direction in which DNA is stored.

Correct answer: B

Rationale: The correct answer is B. The antisense strand runs 3' to 5', which is opposite to the direction of the sense strand. It serves as the template strand for transcription, where an RNA molecule is synthesized complementary to the antisense strand. Choice A is incorrect because the antisense strand runs in the opposite direction. Choice C is incorrect as the antisense strand is primarily involved in transcription, not replication. Choice D is incorrect as the direction of DNA storage is not determined by the antisense strand.

5. What is the process of separating a mixture based on the different boiling points of its components called?

• A. Filtration
• B. Chromatography
• C. Distillation
• D. Centrifugation

Correct answer: C

Rationale: Distillation is the process of separating a mixture based on the different boiling points of its components. During distillation, the mixture is heated to vaporize the component with the lowest boiling point first. The vapor is then cooled and condensed back into a liquid, allowing for the collection of fractions with different boiling ranges. This technique is effective for separating components that have significantly different boiling points. Filtration (Choice A) is a method used to separate solids from liquids or gases using a filter medium. Chromatography (Choice B) is a technique used to separate components of a mixture based on their differential affinities to a stationary phase and a mobile phase. Centrifugation (Choice D) is a process of separating particles from a solution based on differences in size, shape, density, and viscosity by spinning the mixture at high speeds.

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