Nursing Elites

1. Homologous structures are those that:

• A. Have the same function but different origins
• B. Have different functions but the same origin
• C. Are similar in appearance and function due to shared ancestry
• D. Are identical in both appearance and function

Correct answer: C

Rationale: Rationale: - Option A is incorrect because structures with the same function but different origins are analogous structures, not homologous structures. - Option B is incorrect because structures with different functions but the same origin are also not homologous structures; they are considered to be vestigial structures. - Option D is incorrect because structures that are identical in both appearance and function are not necessarily homologous; they could be the result of convergent evolution. Homologous structures are those that share similarities in appearance and function due to being inherited from a common ancestor. These structures may have undergone modifications over time to adapt to different functions in different species, but their fundamental similarities can be traced back to a shared evolutionary history.

2. 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.

3. A playground fence has a rectangular section (5m by 3m) attached to a semicircular section with a radius of 2m. What is the total perimeter?

• A. 13m
• B. 16m
• C. 19m
• D. 22m

Correct answer: D

Rationale: Calculate the semicircle perimeter (π * radius) and add it to the rectangular perimeter: perimeter = π * radius + 2 (length + width) ≈ 3.14 * 2m + 2 (5m + 3m) ≈ 6.28m + 16m ≈ 22.28m ≈ 22m (rounded).

4. During vigorous exercise, the respiratory rate increases to:

• A. Meet the increased demand for oxygen in working muscles
• B. Eliminate excess carbon dioxide more slowly
• C. Conserve energy for physical activity
• D. Decrease the amount of oxygen delivered to the body

Correct answer: A

Rationale: During vigorous exercise, the respiratory rate increases to meet the increased demand for oxygen in working muscles. When we exercise vigorously, our muscles require more oxygen to produce energy through aerobic metabolism. Increasing the respiratory rate allows more oxygen to be taken in and transported to the muscles via the bloodstream to support this increased demand. Option A is correct because it accurately reflects the physiological response of the respiratory system to vigorous exercise, ensuring that working muscles receive sufficient oxygen for optimal performance.

5. Acne vulgaris, commonly known as acne, is primarily caused by

• A. Dry skin (Dry skin can worsen acne but isn't the primary cause)
• B. Clogged pores and excess oil production
• C. Bacterial infection alone (Bacteria play a role but not the sole cause)
• D. Vitamin deficiency

Correct answer: B

Rationale: The correct answer is B: 'Clogged pores and excess oil production.' Acne vulgaris, or acne, is primarily caused by a combination of factors including excess sebum (oil) production by the skin's sebaceous glands and the accumulation of dead skin cells, leading to clogged pores. This environment provides a breeding ground for acne-causing bacteria, contributing to inflammation and the formation of pimples. While factors like dry skin, bacterial infections, and even vitamin deficiencies can exacerbate acne, they are not the primary cause. Thus, B is the most accurate option for the primary cause of acne.

6. The endocrine system communicates through chemical messengers called:

• A. Enzymes
• B. Hormones
• C. Antibodies
• D. Neurons

Correct answer: B

Rationale: The correct answer is B: Hormones. The endocrine system communicates through hormones, which are chemical messengers produced by various glands in the body. These hormones are released into the bloodstream and travel to target organs or tissues to regulate a wide range of bodily functions. Enzymes (A) are biological molecules that catalyze chemical reactions, not chemical messengers for communication within the body. Antibodies (C) are involved in the immune system's response to foreign substances. Neurons (D) are part of the nervous system and communicate through electrical impulses rather than chemical messengers like hormones.

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