Nursing Elites

1. Which of the following statements best defines an organelle?

• A. Layer of polysaccharides outside the plasma membrane of cells.
• B. Abnormal infectious proteins.
• C. Specialized structures within a cell.
• D. Collection of tissues used to serve a specific function.

Correct answer: C

Rationale: The correct answer is C: 'Specialized structures within a cell.' An organelle is a specialized subunit within a cell that has a specific function. Organelles are membrane-bound structures found within the cytoplasm of eukaryotic cells, each performing distinct roles that contribute to the overall functioning of the cell. Choices A, B, and D are incorrect. Option A describes the glycocalyx, which is a layer of polysaccharides outside the plasma membrane of cells. Option B refers to prions, abnormal infectious proteins. Option D defines an organ, a collection of tissues used to serve a specific function, rather than an organelle within a cell.

2. What is the function of the cell membrane?

• A. To protect the cell and control what enters and exits
• B. To store energy
• C. To produce proteins
• D. To synthesize lipids

Correct answer: A

Rationale: The cell membrane, also known as the plasma membrane, serves as a protective barrier for the cell, separating the internal environment of the cell from the external environment. It is selectively permeable, meaning it controls the passage of substances in and out of the cell. This regulation of what enters and exits the cell is crucial for maintaining the cell's internal environment and ensuring proper functioning. Options B, C, and D are incorrect because storing energy, producing proteins, and synthesizing lipids are functions carried out by other cellular structures such as mitochondria, ribosomes, and endoplasmic reticulum, respectively, not the cell membrane.

3. Which hormone is responsible for regulating the body's metabolism?

• A. Insulin
• B. Thyroxine
• C. Melatonin
• D. Adrenaline

Correct answer: B

Rationale: Thyroxine, also known as T4, is produced by the thyroid gland and plays a vital role in regulating the body's metabolism. Insulin is not responsible for regulating metabolism; instead, it helps regulate blood sugar levels. Melatonin is involved in regulating sleep-wake cycles, not metabolism. Adrenaline, also known as epinephrine, is a stress hormone that prepares the body for fight or flight responses, not primarily involved in metabolic regulation.

4. What is the function of arrector pili muscles?

• A. To control sweat production
• B. To contract and cause goosebumps
• C. To produce sebum
• D. To sense touch

Correct answer: B

Rationale: The correct function of arrector pili muscles is to contract and cause goosebumps. These small muscles are attached to hair follicles in mammals. When they contract, they cause the hair to stand on end, resulting in goosebumps. This physiological response is often triggered by cold temperatures or emotional states like fear, helping mammals conserve heat or appear larger in threatening situations. Choices A, C, and D are incorrect. Arrector pili muscles are not involved in controlling sweat production (Choice A), producing sebum (Choice C), or sensing touch (Choice D).

5. Which of the following is an example of a long bone in the human body?

• A. Carpals
• B. Femur
• C. Tarsals
• D. Metacarpals

Correct answer: B

Rationale: The correct answer is B, Femur. The femur is the longest and strongest bone in the human body, located in the thigh region. Long bones are characterized by their elongated shape, such as the femur, which provides support, strength, and mobility. Choices A, C, and D are incorrect because carpal bones (A) are short bones found in the wrist, tarsal bones (C) are short bones found in the ankle, and metacarpal bones (D) are classified as long bones, but they are shorter than the femur and mainly found in the hand.

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