Nursing Elites

1. A scientist observes a new species of plant with unusual leaves. They hypothesize that the leaves help capture more sunlight. Which observation would LEAST support this hypothesis?

• A. The plant grows in shady environments.
• B. The leaves have a large surface area.
• C. The leaves contain high levels of chlorophyll.
• D. The plant has shallow roots.

Correct answer: A

Rationale: If the plant thrives in shade, it suggests the leaves may have adapted for other purposes than maximizing sunlight capture.

2. Osteoporosis is a condition leading to weakened bones and increased risk of fractures. Which hormone plays a key role in bone health and is often affected in osteoporosis?

• A. Estrogen
• B. Testosterone
• C. Thyroid hormone
• D. Insulin

Correct answer: A

Rationale: Estrogen plays a crucial role in bone health by promoting the activity of bone-forming cells and inhibiting bone breakdown. In women, estrogen levels decrease significantly during menopause, leading to a higher risk of osteoporosis. This hormone helps maintain bone density and strength, making it essential for preventing bone loss and fractures. Testosterone, while important for overall health, does not have as significant of an impact on bone health as estrogen does. Thyroid hormone and insulin also have roles in the body, but they are not as directly linked to bone health as estrogen. Therefore, the correct answer is A: Estrogen.

3. What is the term for a genetic disorder caused by a mutation in a mitochondrial gene?

• A. Autosomal dominant disorder
• B. Autosomal recessive disorder
• C. Sex-linked disorder
• D. Mitochondrial disorder

Correct answer: D

Rationale: Rationale: A) Autosomal dominant disorder: This type of genetic disorder is caused by a mutation in one copy of an autosomal gene. It is not related to mitochondrial gene mutations. B) Autosomal recessive disorder: This type of genetic disorder is caused by mutations in both copies of an autosomal gene. It is not related to mitochondrial gene mutations. C) Sex-linked disorder: This type of genetic disorder is caused by mutations in genes located on the sex chromosomes (X or Y). It is not related to mitochondrial gene mutations. D) Mitochondrial disorder: Mitochondrial disorders are genetic disorders caused by mutations in genes located in the mitochondria, the energy-producing structures within cells. These disorders are inherited maternally and can affect various organs and systems in the body due to the role of mitochondria in energy production.

4. Which of the following terms refers to a muscle that lengthens while another muscle contracts to produce movement?

• A. Synergist
• B. Agonist
• C. Antagonist
• D. Flexor

Correct answer: C

Rationale: The correct answer is C: Antagonist. In muscle physiology, an antagonist refers to a muscle that lengthens while another muscle contracts to produce movement. This relationship allows for smooth and coordinated movement by controlling the action of the agonist muscle. For example, when you bend your arm, the biceps muscle (agonist) contracts to flex the arm while the triceps muscle (antagonist) lengthens to allow for this movement. Synergists assist the agonist muscle in performing a movement, while flexors are a type of muscle that decreases the angle between bones at a joint. Therefore, the antagonist best fits the description of a muscle that lengthens while another muscle contracts.

5. The involuntary "fight-or-flight" response is controlled by the:

• A. Sympathetic nervous system
• B. Parasympathetic nervous system
• C. Enteric nervous system
• D. Sensory nervous system

Correct answer: A

Rationale: The correct answer is A: Sympathetic nervous system. The "fight-or-flight" response is an automatic physiological reaction triggered by the sympathetic nervous system in response to a perceived threat or stressor. This system prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. The parasympathetic nervous system, on the other hand, controls the body's "rest-and-digest" response, promoting relaxation and digestion. The enteric nervous system primarily regulates the gastrointestinal system, while the sensory nervous system is responsible for transmitting sensory information to the brain. Therefore, the sympathetic nervous system is specifically responsible for initiating the fight-or-flight response.

6. Which element is used in fire extinguishers to smother flames by displacing oxygen?

• A. Nitrogen
• B. Carbon dioxide
• C. Helium
• D. Argon

Correct answer: B

Rationale: Carbon dioxide extinguishes flames by depriving them of oxygen, preventing the chemical reaction that sustains the fire.

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