Nursing Elites

1. Which hormone is responsible for regulating sleep-wake cycles and is influenced by light exposure?

• A. Melatonin
• B. Cortisol
• C. Estrogen
• D. Glucagon

Correct answer: A

Rationale: The correct answer is A: Melatonin. Melatonin is the hormone responsible for regulating sleep-wake cycles, also known as the circadian rhythm. Its production is influenced by light exposure, with levels increasing in the evening in response to darkness, signaling the body that it is time to sleep. Choice B, cortisol, is a stress hormone and does not directly regulate sleep-wake cycles. Choice C, estrogen, is a sex hormone and is not primarily involved in regulating sleep. Choice D, glucagon, is a hormone that increases blood glucose levels and is not related to sleep-wake cycles.

2. How does an increase in temperature generally affect the solubility of most solid solutes in a liquid solvent?

• A. It increases solubility
• B. It decreases solubility
• C. It has no effect on solubility
• D. It depends on the nature of the solute

Correct answer: A

Rationale: In general, increasing temperature tends to increase the solubility of most solid solutes in liquid solvents. This occurs because higher temperatures provide more energy for the solvent molecules to break the solute-solvent attractive forces and allow more solute to dissolve. The increase in temperature facilitates the dissolution process by overcoming the intermolecular forces that hold the solute particles together. Choice B is incorrect because higher temperatures typically lead to greater solubility. Choice C is incorrect as temperature changes usually impact solubility. Choice D is incorrect because although the nature of the solute can influence solubility, the general trend is that higher temperatures enhance solubility for most solid solutes in liquid solvents.

3. Which protein complex in the sarcomere is responsible for the thick filament?

• A. Actin
• B. Myosin
• C. Tropomyosin
• D. Troponin

Correct answer: B

Rationale: Myosin is the protein complex responsible for the thick filament in the sarcomere. It interacts with actin, another protein in the sarcomere, to generate the sliding movement that results in muscle contraction. Actin is a thin filament protein that interacts with myosin to create the sliding filament mechanism. Tropomyosin and troponin are regulatory proteins that regulate muscle contraction by controlling the interaction between actin and myosin, rather than directly being responsible for the thick filament.

4. Which of the following factors would NOT affect the solubility of a solid solute in a liquid solvent?

• A. Temperature
• B. Pressure
• C. Particle size
• D. Nature of the solute and solvent

Correct answer: B

Rationale: Pressure does not typically affect the solubility of a solid solute in a liquid solvent. Solubility is primarily influenced by factors such as temperature, particle size, and the nature of the solute and solvent. Increasing pressure generally has a minimal effect on the solubility of solids in liquids. The impact of pressure on solubility is more significant for gases in liquids rather than solids in liquids. Therefore, option B is the correct answer. Options A, C, and D directly impact the solubility of a solid solute in a liquid solvent. Temperature affects the solubility as it changes the kinetic energy of particles, particle size can impact the surface area available for interaction between solute and solvent, and the nature of the solute and solvent influences their intermolecular interactions and compatibility.

5. What is the basic structural and functional unit of the kidney?

• A. Neuron
• B. Nephron
• C. Glomerulus
• D. Axon

Correct answer: B

Rationale: The correct answer is B, Nephron. The nephron is indeed the basic structural and functional unit of the kidney. It is responsible for filtering blood, regulating electrolytes, maintaining fluid balance, and removing waste products. Choice A, Neuron, is incorrect as neurons are nerve cells, not specific to kidney function. Choice C, Glomerulus, is a component of the nephron but not the entire functional unit. Choice D, Axon, is a part of nerve cells and is not related to kidney structure or function.

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