Nursing Elites

1. Which of the following best defines the term amphoteric?

• A. A substance that conducts electricity due to ionization when dissolved in a solvent
• B. A substance that can act as an acid or a base depending on the properties of the solute
• C. A substance that, according to the Brønsted-Lowry Acid-Base Theory, is a proton-donor
• D. A substance that donates its proton and forms its conjugate base in a neutralization reaction

Correct answer: B

Rationale: An amphoteric substance can act as both an acid or a base depending on the environment. It can donate a proton (act as an acid) or accept a proton (act as a base), showing versatility in its behavior. Choice A is incorrect as it describes an electrolyte rather than an amphoteric substance. Choice C is incorrect as it defines an acid based on the Brønsted-Lowry Acid-Base Theory. Choice D is incorrect as it specifically refers to a substance donating a proton in a neutralization reaction, not capturing the dual behavior of an amphoteric substance.

2. What is the function of the cell membrane?

• A. To protect the cell and control what enters and exits
• B. To store energy
• C. To produce proteins
• D. To synthesize lipids

Correct answer: A

Rationale: The cell membrane, also known as the plasma membrane, serves as a protective barrier for the cell, separating the internal environment of the cell from the external environment. It is selectively permeable, meaning it controls the passage of substances in and out of the cell. This regulation of what enters and exits the cell is crucial for maintaining the cell's internal environment and ensuring proper functioning. Options B, C, and D are incorrect because storing energy, producing proteins, and synthesizing lipids are functions carried out by other cellular structures such as mitochondria, ribosomes, and endoplasmic reticulum, respectively, not the cell membrane.

3. Which hormone is produced by the adrenal glands in response to stress?

• A. Insulin
• B. Adrenaline
• C. Glucagon
• D. Thyroxine

Correct answer: B

Rationale: Adrenaline, also known as epinephrine, is produced by the adrenal glands in response to stress. It helps prepare the body for the 'fight or flight' response by increasing heart rate, dilating airways, and mobilizing energy sources. Choice A, Insulin, is incorrect as it is produced by the pancreas and regulates blood sugar levels. Choice C, Glucagon, is also produced by the pancreas and functions to increase blood glucose levels. Choice D, Thyroxine, is produced by the thyroid gland and regulates metabolism, not specifically in response to stress.

4. What is the main function of lysosomes?

• A. Breaking down and recycling cellular waste
• B. Storing carbohydrates
• C. Synthesizing lipids
• D. Transcribing DNA into mRNA

Correct answer: A

Rationale: The main function of lysosomes is to break down and recycle cellular waste materials, such as old organelles, foreign substances, and cellular debris. This process is crucial for maintaining cellular homeostasis and proper functioning. Storing carbohydrates (B), synthesizing lipids (C), and transcribing DNA into mRNA (D) are not functions typically associated with lysosomes. Storing carbohydrates is primarily done by other organelles like vacuoles. Synthesizing lipids is a function usually associated with the endoplasmic reticulum and transcribing DNA into mRNA occurs in the nucleus by the process of transcription.

5. Which part of the brain is responsible for controlling voluntary muscle movements?

• A. Cerebrum
• B. Cerebellum
• C. Medulla oblongata
• D. Thalamus

Correct answer: A

Rationale: The correct answer is the Cerebrum. The cerebrum, the largest part of the brain, controls voluntary muscle movements, along with cognitive functions like thinking, perception, and decision-making. It is crucial for motor coordination and the regulation of voluntary movements. The Cerebellum (Choice B) is responsible for coordinating movement, balance, and posture, but not specifically for voluntary muscle movements. The Medulla oblongata (Choice C) is involved in controlling autonomic functions like breathing and heart rate, not voluntary muscle movements. The Thalamus (Choice D) acts as a relay station for sensory information but is not primarily responsible for controlling voluntary muscle movements.

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