Nursing Elites

1. Which organelle in the cell is responsible for protein synthesis?

• A. Ribosome
• B. Nucleus
• C. Mitochondrion
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A: Ribosome. Ribosomes are the organelles responsible for protein synthesis in the cell. They are the cellular machinery where translation, the process of assembling proteins from amino acids based on mRNA sequences, occurs. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum. The nucleus (choice B) houses DNA but is not directly involved in protein synthesis. Mitochondria (choice C) are responsible for energy production through cellular respiration, not protein synthesis. The Golgi apparatus (choice D) is involved in modifying, sorting, and packaging proteins for secretion, not in the synthesis of proteins.

2. Which structure in the respiratory system is responsible for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream?

• A. Trachea
• B. Bronchi
• C. Alveoli
• D. Bronchioles

Correct answer: C

Rationale: The alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs. Oxygen from the air diffuses into the bloodstream through the alveoli, while carbon dioxide from the bloodstream diffuses into the alveoli to be exhaled. The trachea, bronchi, and bronchioles are essential parts of the airway system responsible for transporting air to and from the lungs but do not directly participate in the gas exchange process. Therefore, option C, the alveoli, is the correct answer for the structure responsible for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream.

3. What is the process by which cells respond to external stimuli, such as chemicals, temperature, or touch, called?

• A. Signal transduction
• B. Homeostasis
• C. Adaptation
• D. Metabolism

Correct answer: A

Rationale: Signal transduction is the correct answer. It is the process by which cells respond to external stimuli like chemicals, temperature, or touch. When a cell receives a signal from its environment, it triggers a series of molecular events leading to a specific cellular response. This process involves transmitting signals from the cell surface to the interior, triggering various cellular activities. Homeostasis, on the other hand, refers to an organism's ability to maintain internal stability in response to external changes. Adaptation involves an organism adjusting to its environment over time through genetic changes or behavioral modifications, which is distinct from the process of cells responding to immediate external stimuli. Metabolism, although essential for cellular functions, is not specifically about cells responding to external stimuli but rather the biochemical processes involved in energy production, storage, and utilization within cells.

4. When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

• A. Negative feedback.
• B. Positive feedback.
• C. Stress response.
• D. Parasympathetic regulation.

Correct answer: A

Rationale: This mechanism is an example of negative feedback. Negative feedback systems work to counteract changes in the body and maintain a stable internal environment (homeostasis). In this case, the release of insulin in response to high glucose levels is followed by a reduction in insulin release when glucose levels drop. This response helps regulate glucose levels and return them to a normal range, demonstrating the characteristic of negative feedback where the body's response opposes the initial stimulus to maintain equilibrium. Positive feedback would amplify the initial change rather than counteract it, so it is not the correct choice. Stress response and parasympathetic regulation are not directly involved in this glucose regulation process, making them incorrect choices.

5. What is the primary function of the small intestine?

• A. To absorb water
• B. To absorb nutrients
• C. To store waste
• D. To produce enzymes

Correct answer: B

Rationale: The correct answer is B: "To absorb nutrients." The small intestine's primary function is to absorb nutrients from digested food. It plays a crucial role in the digestion and absorption of nutrients such as proteins, carbohydrates, fats, vitamins, and minerals, which are essential for the body's functions and energy production. Choice A, "To absorb water," is incorrect because the absorption of water primarily occurs in the large intestine. Choice C, "To store waste," is incorrect as waste is stored in the large intestine before elimination. Choice D, "To produce enzymes," is incorrect because while the small intestine does receive enzymes from other organs to aid in digestion, its primary role is not enzyme production.

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