Nursing Elites

1. A closed system in ecology is one that:

• A. Exchanges energy but not matter
• B. Exchanges both energy and matter
• C. Exchanges neither energy nor matter
• D. Recycles nutrients efficiently

Correct answer: A

Rationale: Rationale: In ecology, a closed system is one that does not exchange matter with its surroundings but can exchange energy. This means that while energy can enter or leave the system, the amount of matter within the system remains constant. This definition aligns with option A, making it the correct answer. Options B and C are incorrect because a closed system does not exchange matter, and option D is not directly related to the definition of a closed system in ecology.

2. During gas exchange in the alveoli, what happens to oxygen?

• A. Oxygen is released from the bloodstream into the alveoli.
• B. Oxygen is absorbed from the alveoli into the bloodstream.
• C. Oxygen is converted into carbon dioxide.
• D. Oxygen is stored in the alveoli for later use.

Correct answer: B

Rationale: During gas exchange in the alveoli, oxygen is absorbed from the alveoli into the bloodstream. In the alveoli, oxygen diffuses across the thin walls of the alveoli and into the surrounding capillaries where it binds to hemoglobin in red blood cells. This oxygen-rich blood is then transported to the body's tissues for cellular respiration. Therefore, option B is correct as it accurately describes the direction of oxygen movement during the process of gas exchange in the lungs.

3. Which hormone, produced by the thyroid gland, plays a key role in regulating calcium levels in the blood by promoting calcium release from bones and increasing calcium reabsorption in the kidneys?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: b

Rationale: The correct answer is B: Parathyroid hormone (PTH). PTH is produced by the parathyroid glands, not the thyroid gland. PTH plays a crucial role in regulating calcium levels in the blood by promoting calcium release from bones and increasing calcium reabsorption in the kidneys. This hormone acts in opposition to calcitonin, which is produced by the thyroid gland and works to lower blood calcium levels by promoting calcium deposition into bones. Thyroxine (C) is a thyroid hormone that regulates metabolism, not calcium levels. Insulin (D) is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels.

4. What happens to the acceleration of an object when the force acting on it is increased, assuming the mass remains constant?

• A. Acceleration increases
• B. Acceleration decreases
• C. Acceleration remains constant
• D. Acceleration becomes zero

Correct answer: a

Rationale: According to Newton's second law (F = ma), if mass is constant and force increases, acceleration also increases.

5. What is the law that states energy can neither be created nor destroyed?

• A. Law of Conservation of Matter
• B. Law of Conservation of Energy
• C. Law of Universal Gravitation
• D. Law of Inertia

Correct answer: B

Rationale: Law of Conservation of Energy. This law applies to both chemical and physical processes, including chemical reactions.

6. The hormone responsible for the "fight-or-flight" response in stressful situations is produced by the:

• A. Thyroid gland
• B. Pituitary gland
• C. Adrenal gland
• D. Pancreas

Correct answer: C

Rationale: The correct answer is C: Adrenal gland. The adrenal gland is responsible for producing the hormone known as adrenaline, which triggers the 'fight-or-flight' response in stressful situations. This response prepares the body to either confront the stressor or flee from it. The thyroid gland (A) is responsible for producing hormones that regulate metabolism, growth, and development. The pituitary gland (B) controls several other endocrine glands and produces a variety of hormones. The pancreas (D) is responsible for producing insulin and glucagon, which regulate blood sugar levels but are not directly involved in the 'fight-or-flight' response.

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