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. What is the molarity of a solution made by dissolving 4.0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23.0 g/mol, and Cl is 35.5 g/mol.

• A. 0.34 M
• B. 0.57 M
• C. 0.034 M
• D. 0.057 M

Correct answer: B

Rationale: To find the molarity, first calculate the moles of NaCl. Moles of NaCl = 4.0 g / (23.0 g/mol + 35.5 g/mol) = 0.068 mol. Next, use the formula for molarity: Molarity = moles of solute / liters of solution. Molarity = 0.068 mol / 0.120 L = 0.57 M. Therefore, the molarity of the solution is 0.57 M. Choice A, 0.34 M, is incorrect as it does not match the calculated molarity. Choice C, 0.034 M, is incorrect as it is a decimal point off from the correct molarity. Choice D, 0.057 M, is incorrect as it does not match the calculated molarity of 0.57 M.

3. When unpolarized light passes through a polarizing filter, the intensity of the transmitted light is:

• A. Completely absorbed
• B. Reduced by half
• C. Unaffected
• D. Doubled

Correct answer: B

Rationale: When unpolarized light passes through a polarizing filter, the filter only allows light waves oscillating in a specific direction to pass through while blocking light waves oscillating in other directions. Since unpolarized light consists of light waves oscillating in all possible directions, when it passes through a polarizing filter, only half of the light waves (those oscillating in the direction allowed by the filter) are transmitted. As a result, the intensity of the transmitted light is reduced by half. Choice A is incorrect because the light is not completely absorbed; choice C is incorrect because the polarizing filter affects the transmitted light; and choice D is incorrect because the intensity does not double, but rather decreases by half due to the selective transmission of light waves in a specific direction by the polarizing filter.

4. What is the process of splitting a heavy nucleus into smaller nuclei, releasing a vast amount of energy called?

• A. Nuclear fusion
• B. Nuclear fission
• C. Radioactive decay
• D. Chain reaction

Correct answer: B

Rationale: The correct answer is B: Nuclear fission. Nuclear fission is the process of splitting a heavy nucleus into smaller nuclei, releasing a vast amount of energy. This process is commonly used in nuclear power plants and nuclear weapons. It is a controlled chain reaction that generates energy. Option A, Nuclear fusion, is the process of combining two light nuclei to form a heavier nucleus, releasing energy. This process powers the sun and other stars. Option C, Radioactive decay, is the process by which an unstable atomic nucleus loses energy by emitting radiation. Option D, Chain reaction, is a self-sustaining reaction where the products of one reaction event stimulate further reaction events. While chain reactions can occur in both nuclear fission and fusion, the specific process of splitting a heavy nucleus into smaller ones is known as nuclear fission.

5. What is the process by which muscles convert chemical energy (ATP) into mechanical energy (movement)?

• A. Photosynthesis
• B. Cellular respiration
• C. Muscle contraction
• D. The sliding filament theory

Correct answer: C

Rationale: Muscle contraction is the correct answer. It is the process by which muscles convert chemical energy (ATP) into mechanical energy (movement). During muscle contraction, the sliding filament theory explains how actin and myosin filaments slide past each other, causing muscle fibers to shorten and generate force. Photosynthesis (option A) is the process by which plants convert light energy into chemical energy. Cellular respiration (option B) is the process by which cells generate ATP from glucose and oxygen. The sliding filament theory (option D) is a detailed explanation of the molecular events that occur during muscle contraction but is not the overall process of converting energy into movement; it focuses on the mechanism within the process of muscle contraction.

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