Nursing Elites

1. Which of the following is NOT a function of the nervous system?

• A. Detecting touch
• B. Regulating body temperature
• C. Producing insulin
• D. Controlling muscle movement

Correct answer: C

Rationale: The nervous system is responsible for detecting touch (option A), regulating body temperature (option B), and controlling muscle movement (option D). Producing insulin (option C) is a function of the endocrine system, which produces hormones like insulin to regulate metabolism and glucose levels. Therefore, option C is the correct answer as it is not a function of the nervous system.

2. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

3. What is the initial step of the scientific method?

• A. construct a hypothesis
• B. make observations
• C. analyze data
• D. form a question

Correct answer: B

Rationale: The first step of the scientific method is to make observations. This involves collecting data and information about a specific phenomenon or problem. Observations serve as the basis for developing a question to be explored further. Forming a hypothesis (Choice A) comes after making observations, as the hypothesis is an educated guess to explain the observations. Analyzing data (Choice C) occurs later in the scientific method after data has been collected and experiments conducted. Forming a question (Choice D) is a crucial step but typically follows observations in the scientific process.

4. How many moles of water are produced when 0.5 moles of methane (CH4) react with excess oxygen?

• A. 0.5 moles
• B. 1 mole
• C. 2 moles
• D. 3 moles

Correct answer: B

Rationale: The balanced chemical equation for the combustion of methane is: CH4 + 2O2 -> CO2 + 2H2O. This equation shows that 1 mole of methane produces 2 moles of water. Therefore, when 0.5 moles of methane react, they will produce 1 mole of water. The ratio of water to methane is 2:1, meaning that for every mole of methane that reacts, it produces 2 moles of water. Since only 0.5 moles of methane are reacting, the amount of water produced will be half of what would be produced if 1 mole of methane reacted, resulting in 1 mole of water being produced. Choice A is incorrect because it does not consider the stoichiometry of the reaction. Choices C and D are incorrect as they do not align with the balanced chemical equation and the stoichiometric ratios involved in the reaction.

5. Which organ produces insulin, a hormone responsible for regulating blood sugar levels?

• A. Parathyroid gland
• B. Pancreas
• C. Thymus gland
• D. Ovaries

Correct answer: B

Rationale: Insulin is a hormone produced by the pancreas. Beta cells located in the islets of Langerhans within the pancreas are responsible for insulin production. Insulin plays a crucial role in regulating blood sugar levels by promoting the uptake of glucose into cells, thereby maintaining blood sugar levels within a normal range. Choices A, C, and D are incorrect because the parathyroid gland is primarily involved in regulating calcium levels, the thymus gland is involved in immune function, and the ovaries are involved in reproductive functions, not insulin production for blood sugar regulation.

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