Nursing Elites

1. The shimmering image of water seen on a hot road is a well-known example of:

• A. Reflection
• B. Refraction
• C. Interference
• D. Polarization

Correct answer: B

Rationale: The shimmering image of water seen on a hot road is a result of refraction, not reflection. Refraction is the bending of light as it passes from one medium to another of different optical density. In this case, the hot air just above the road has a different density than the cooler air above it, causing light to bend and create the illusion of water on the road. Refraction is the most suitable explanation for this phenomenon, as it involves the bending of light rays due to the change in the medium's optical density, producing the visual effect observed on the hot road. Reflection, interference, and polarization do not involve the bending of light due to changes in optical density and are not applicable to the scenario described on the hot road.

2. 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.

3. What is the process by which a population gradually loses genetic variation?

• A. Founder effect
• B. Bottleneck effect
• C. Gene flow
• D. Speciation

Correct answer: B

Rationale: A) Founder effect: This occurs when a small group of individuals establishes a new population, leading to a loss of genetic variation compared to the original population. It does not necessarily result in a gradual loss of genetic variation in an existing population. B) Bottleneck effect: This process occurs when a population is drastically reduced in size, leading to a significant loss of genetic variation due to the limited number of individuals contributing to the gene pool. The reduced genetic diversity can have long-term effects on the population's ability to adapt to environmental changes. C) Gene flow: This refers to the movement of genes between populations, which can introduce new genetic variation and prevent populations from diverging. Gene flow does not lead to a gradual loss of genetic variation within a population. D) Speciation: This is the process by which new species evolve from existing species, often involving the accumulation of genetic differences that l

4. How do killer T cells recognize infected cells?

• A. The B cells flag the infected cells with amino acids.
• B. Tiny bits of the virus's RNA are left around the cell.
• C. Macrophages show up to help consume the infected cell.
• D. The T cells have receptors that recognize the proteins the virus leaves on the surface of the cell.

Correct answer: D

Rationale: Killer T cells recognize infected cells by detecting viral proteins displayed on the surface of these cells. The T cells possess receptors specifically designed to identify these viral proteins, allowing them to target and eliminate the infected cells. Choice A is incorrect because B cells are not directly involved in the recognition process of infected cells by killer T cells. Choice B is incorrect because tiny bits of the virus's RNA being left around the cell is not how killer T cells primarily recognize infected cells. Choice C is incorrect because while macrophages play a role in immune responses, they do not directly assist in the recognition of infected cells by killer T cells.

5. What does the term 'colligative property' refer to in solutions?

• A. Properties that depend on the nature of the solute particles
• B. Properties that depend on the concentration of solute particles
• C. Properties that depend on the temperature of the solution
• D. Properties that depend on the pressure of the solution

Correct answer: B

Rationale: Colligative properties are properties of a solution that depend on the concentration of solute particles, regardless of the identity of the solute. These properties include lowering the vapor pressure, elevation of boiling point, depression of freezing point, and osmotic pressure. The concentration of solute particles affects these properties, not the nature, temperature, or pressure of the solution. Therefore, choice B is the correct answer as it accurately reflects the definition of colligative properties. Choices A, C, and D are incorrect because colligative properties are not based on the nature, temperature, or pressure of the solute, but rather on the concentration of solute particles in the solution.

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