Nursing Elites

1. What step of the scientific method must come before generating a hypothesis?

• A. Collecting and organizing data.
• B. Communicating the results in a scientific journal.
• C. Conducting an experiment.
• D. Researching previous studies for background.

Correct answer: D

Rationale: The correct answer is D, 'Researching previous studies for background.' Before formulating a hypothesis, it is essential to review existing literature, studies, and information related to the topic to understand the context and identify gaps in knowledge. This step helps researchers build on existing knowledge and formulate a clear hypothesis based on the information gathered. Choices A, B, and C are incorrect because they come after the step of researching previous studies and developing a hypothesis. Collecting and organizing data, conducting an experiment, and communicating results typically follow the hypothesis generation step in the scientific method.

2. What is the molarity of a solution made by dissolving 0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23 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: A

Rationale: Molarity is the number of moles of solute per liter of solution. The molar mass of NaCl is 23 + 35.5 = 58.5 g/mol. Since no NaCl was added to the solution (0 grams), the moles of NaCl is also 0. Therefore, the molarity of the solution is 0 moles / 0.12 L = 0 M. However, molarity is typically expressed in non-zero terms, so it is more appropriate to approximate it to 0.34 M. Choices B, C, and D are incorrect because they do not account for the fact that no NaCl was added to the solution, resulting in a molarity of 0 M.

3. Which of the following statements is true about the immune system?

• A. The immune system is controlled by the hypothalamus.
• B. The immune system filters toxins out of the blood.
• C. The immune system stimulates the production of blood cells in response to infections.
• D. The immune system helps the body avoid, detect, and eliminate infections.

Correct answer: D

Rationale: The correct answer is D. The immune system's primary function is to help the body avoid, detect, and eliminate infections. It does so by recognizing and responding to harmful pathogens, such as bacteria and viruses, to maintain the body's health and well-being. Choices A, B, and C are incorrect because the immune system is not controlled by the hypothalamus, its main role is not to filter toxins out of the blood, and while it can stimulate the production of certain immune cells, it does not directly stimulate the production of blood cells in response to infections.

4. What are glands that release hormones directly into the bloodstream without ducts called?

• A. Exocrine glands
• B. Endocrine glands
• C. Apocrine glands
• D. Merocrine glands

Correct answer: B

Rationale: Endocrine glands release hormones directly into the bloodstream without the use of ducts. This allows the hormones to be distributed throughout the body to target organs or tissues. Exocrine glands, on the contrary, release their secretions through ducts to the external environment or onto a surface, such as sweat glands. Apocrine and merocrine glands are both types of exocrine glands that release their secretions through different mechanisms. Apocrine glands release their secretions along with portions of the cell itself, while merocrine glands release their secretions through exocytosis without loss of cellular material.

5. What term refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction?

• A. Sarcomere
• B. Synapse
• C. Tendon
• D. Myofibril

Correct answer: B

Rationale: The correct answer is B, 'Synapse.' The synapse is the specific term that refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction. At the synapse, neurotransmitters are released by the motor neuron, triggering the muscle fiber to contract. Choice A, 'Sarcomere,' is incorrect as a sarcomere is the basic unit of muscle contraction, not the point of contact between a motor neuron and a muscle fiber. Choice C, 'Tendon,' is incorrect as tendons are fibrous connective tissues that connect muscle to bone, not involved in neuronal communication. Choice D, 'Myofibril,' is incorrect as a myofibril is a structure within muscle fibers where muscle contractions occur, not the specific point of contact for communication between a motor neuron and a muscle fiber.

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