Nursing Elites

1. Which of the following correctly identifies a difference between the primary and secondary immune response?

• A. In the secondary response, macrophages migrate to the lymph nodes to present the foreign microorganism to helper T lymphocytes.
• B. The humoral immunity that characterizes the primary response is coordinated by B lymphocytes.
• C. The primary response is quicker and more powerful than the secondary response.
• D. Suppressor T cells are activated in the secondary response to prevent an overactive immune response.

Correct answer: C

Rationale: The correct answer is C. The primary immune response is slower and less powerful compared to the secondary immune response. During the primary response, immune cells encounter the antigen for the first time, necessitating the activation and proliferation of specific immune cells. In contrast, the secondary response benefits from memory cells that quickly recognize the antigen, enabling a faster and more potent immune response. Choices A, B, and D are incorrect. While macrophages play a role in presenting antigens to T cells, this is not a defining difference between primary and secondary responses. Humoral immunity involves B lymphocytes in both primary and secondary responses, so it does not differentiate the two. Suppressor T cells primarily function to regulate the immune response but are not a key factor distinguishing primary from secondary responses.

2. Which of the following scenarios represents an example of static friction?

• A. Sliding a heavy box across the floor
• B. A car moving around a curve
• C. Pushing a stationary object
• D. Braking a car to stop

Correct answer: C

Rationale: The correct answer is C. Static friction occurs when two surfaces are in contact but not moving relative to each other. Pushing a stationary object involves static friction as you apply a force to overcome the friction keeping the object stationary. Choices A, B, and D involve kinetic friction, which occurs when two surfaces are moving relative to each other. Option A involves moving the box across the floor, which is an example of kinetic friction. Option B involves the movement of a car around a curve, which also relates to kinetic friction due to the relative movement between the tires and the road. Option D describes braking a car to stop, where the moving car's wheels interact with the road, creating kinetic friction to slow down and stop the car.

3. What describes the change in direction of light when it passes through different mediums, such as air and water?

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

Correct answer: C

Rationale: Refraction is the change in direction of light as it moves from one medium to another, such as air to water or glass. This change occurs due to variations in the speed of light in each medium, causing the light rays to bend. When light passes through different mediums, it changes its path, a phenomenon known as refraction. Choice A, Diffraction, refers to the bending of waves around obstacles and the spreading of waves when passing through small openings, not the change in direction of light when moving between mediums. Choice B, Reflection, is the bouncing back of light rays from a surface into the same medium, not the change in direction when transitioning between different mediums. Choice D, Dispersion, involves the separation of light into its constituent colors based on their different wavelengths, not the change in direction of light when passing through different mediums.

4. Which of the following is NOT a common symptom of lactose intolerance?

• A. Gas
• B. Bloating
• C. Diarrhea
• D. Nausea

Correct answer: D

Rationale: A) Gas: Gas is a common symptom of lactose intolerance. When lactose is not properly digested, it can ferment in the colon, leading to the production of gas. B) Bloating: Bloating is another common symptom of lactose intolerance. The buildup of gas in the digestive system can cause bloating and discomfort. C) Diarrhea: Diarrhea is a common symptom of lactose intolerance. When lactose is not broken down in the small intestine, it can draw excess water into the colon, resulting in diarrhea. D) Nausea: Nausea is not a common symptom of lactose intolerance. While some individuals may experience mild stomach discomfort or cramps, nausea is not typically associated with lactose intolerance.

5. The Hardy-Weinberg equilibrium describes a population that is:

• A. Undergoing rapid evolution due to strong directional selection.
• B. Not evolving and at genetic equilibrium with stable allele frequencies.
• C. Experiencing a founder effect leading to a reduction in genetic diversity.
• D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

Similar Questions