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. Tissues are groups of cells with similar:

• A. Appearance only
• B. Function and structure
• C. Location only
• D. Age only

Correct answer: B

Rationale: The correct answer is B: 'Function and structure.' Tissues are groups of cells that work together to perform a specific function in the body. These cells have both similar functions, such as carrying out a specific task like contracting in muscle tissue, and similar structures, such as having similar shapes or types of organelles. This allows them to work together efficiently and effectively. Choices A, C, and D are incorrect because tissues are defined by more than just appearance, location, or age; they are primarily characterized by their shared function and structure.

3. Which of the following blood vessels carries oxygenated blood from the lungs back to the left atrium of the heart?

• A. Pulmonary artery
• B. Pulmonary vein
• C. Aorta
• D. Inferior vena cava

Correct answer: B

Rationale: The correct answer is B: Pulmonary vein. The pulmonary vein is the blood vessel that carries oxygenated blood from the lungs back to the heart. Oxygenated blood flows from the lungs through the pulmonary veins to the left atrium of the heart, where it is then pumped out to the rest of the body through the aorta. The pulmonary artery, on the other hand, carries deoxygenated blood from the heart to the lungs for oxygenation. The aorta is the largest artery in the body and carries oxygenated blood from the heart to the rest of the body. The inferior vena cava carries deoxygenated blood from the lower body back to the right atrium of the heart. Therefore, the correct choice is B, the pulmonary vein, as it specifically carries oxygenated blood from the lungs back to the left atrium of the heart.

4. What is the primary hormone released by the parathyroid glands?

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

Correct answer: C

Rationale: The primary hormone released by the parathyroid glands is Parathyroid hormone (PTH), which plays a crucial role in regulating calcium levels in the body. Insulin is produced by the pancreas to regulate blood sugar levels and is unrelated to the parathyroid glands. Calcitonin is produced by the thyroid gland and helps regulate calcium levels but is not the primary hormone released by the parathyroid glands. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism and is also not released by the parathyroid glands. Therefore, the correct answer is C: Parathyroid hormone (PTH).

5. What is the Doppler effect, and how does it explain the shift in frequency of sound waves perceived by an observer?

• A. It only affects light waves, not sound waves.
• B. It's the change in wave speed due to medium density.
• C. It's the perceived change in frequency due to relative motion.
• D. It's the bending of waves due to different mediums.

Correct answer: C

Rationale: The Doppler effect describes how the perceived frequency of a wave changes depending on the relative motion between the source and observer. For example, an approaching siren sounds higher pitched due to compressed wavefronts, while a receding siren sounds lower due to stretched wavefronts.

6. Which term describes the resistance of a substance to being hammered into different shapes?

• A. Viscosity
• B. Ductility
• C. Malleability
• D. Conductivity

Correct answer: c

Rationale: Malleability refers to the resistance of a substance to being hammered or pressed into different shapes without breaking.

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