Nursing Elites

1. What phenomenon explains the formation of rainbows in the sky?

• A. Diffraction
• B. Interference
• C. Refraction and dispersion of sunlight by water droplets
• D. Reflection from clouds

Correct answer: C

Rationale: Rainbows are formed due to the refraction and dispersion of sunlight by water droplets in the atmosphere. When sunlight enters a water droplet, it is refracted, then internally reflected, and finally refracted again as it exits the droplet. This dispersion of light into its component colors creates the beautiful rainbow we see in the sky. Choice A, diffraction, involves bending of light around obstacles or through narrow openings, not the splitting of light into colors as seen in rainbows. Choice B, interference, refers to the phenomenon where two or more light waves overlap and interact, producing a pattern of light and dark bands, which is not the case with rainbows. Choice D, reflection from clouds, does not accurately describe the process involved in the formation of rainbows through refraction and dispersion of light by water droplets.

2. Which of the following terms refers to the degeneration of nerve tissue?

• A. Potentiation
• B. Demyelination
• C. Reuptake
• D. Neurogenesis

Correct answer: B

Rationale: Demyelination specifically refers to the degeneration of the myelin sheath that covers nerve fibers. When demyelination occurs, nerve function and communication can be impaired. Potentiation involves the strengthening of synaptic connections, reuptake is the reabsorption process of neurotransmitters by the presynaptic neuron, and neurogenesis is the generation of new neurons. Therefore, the correct term for the degeneration of nerve tissue among the options provided is demyelination.

3. The process by which two or more species reciprocally influence each other's evolution through selection pressures exerted on one another is called:

• A. Convergent evolution
• B. Divergent evolution
• C. Coevolution
• D. Coevolution

Correct answer: C

Rationale: A) Convergent evolution refers to the process by which unrelated species evolve similar traits due to similar environmental pressures. This does not involve reciprocal influence between species. B) Divergent evolution refers to the process by which two or more related species become more dissimilar over time due to different selection pressures. This also does not involve reciprocal influence between species. C) Coevolution is the process by which two or more species reciprocally influence each other's evolution through selection pressures exerted on one another. This can lead to a close ecological relationship between the species, such as in predator-prey interactions or mutualistic relationships. D) This option is a duplicate of option C.

4. A 10 kg box rests on a frictionless surface. A horizontal force of 20 N is applied to the box. What is the box's acceleration?

• A. 0.5 m/s²
• B. 1 m/s²
• C. 2 m/s²
• D. 10 m/s²

Correct answer: B

Rationale: The acceleration of an object is given by the formula \(a = \frac{F}{m}\), where \(F\) is the net force acting on the object and \(m\) is the mass of the object. In this case, the net force acting on the box is 20 N, and the mass of the box is 10 kg. Plugging these values into the formula, we get \(a = \frac{20}{10} = 2\) m/s².

5. Which property of a substance measures the amount of matter per unit volume?

• A. Density
• B. Mass
• C. Weight
• D. Volume

Correct answer: A

Rationale: Density is the property of a substance that measures the amount of matter per unit volume. It is calculated by dividing the mass of the substance by its volume. Mass refers to the amount of matter in an object, weight is the force of gravity acting on an object, and volume is the amount of space an object occupies. Density specifically quantifies how tightly packed the matter in a substance is, providing a measure of compactness or concentration of matter. Therefore, the correct answer is A, Density.

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