Which of the following statements best defines an organelle?

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.

Correct Answer: D

Rationale: Homeostasis is defined as the tendency of the body to maintain a stable internal environment despite external changes. This process involves regulating various physiological parameters such as body temperature, blood pressure, and glucose levels to ensure optimal functioning and health. Option A is incorrect as it specifically refers to body weight regulation, which is not the sole focus of homeostasis. Option B is incorrect as it describes maintaining a constant temperature in a room, rather than the internal environment of the body. Option C is incorrect as it only addresses the prevention of hunger pains through food ingestion, which is not the overarching concept of homeostasis.

Correct Answer: B

Rationale: When a patient is lying flat on their back, they are in the supine position. In the supine position, the person's face is facing upward, and their back is touching the surface they are lying on. This position is commonly used for medical examinations and procedures. Choice A, 'Prone,' refers to lying face down, not on the back. Choice C, 'Lateral,' indicates lying on the side. Choice D, 'Medial,' pertains to the middle or center, not a position in relation to lying on the back.

Correct Answer: B

Rationale: The corrected question focuses on the consequence of bone marrow failure, which is pancytopenia. Bone marrow failure results in decreased production of red blood cells, white blood cells, and platelets, leading to pancytopenia. This condition manifests as fatigue, weakness, increased infection susceptibility, and bleeding tendencies. Paraplegia, seizures, and pathologic fractures are not typical outcomes of bone marrow failure. Paraplegia is associated with spinal cord injury, seizures with neurological disorders, and pathologic fractures with conditions like osteoporosis or bone tumors.

Correct Answer: C

Rationale: In acute appendicitis, nonpregnant patients with normal anatomy commonly experience pain in the right lower quadrant of the abdomen. The pain usually starts around the umbilicus or epigastric area and then migrates to the right lower quadrant as inflammation progresses in the appendix. This classic migration of pain is known as McBurney's point tenderness and is a key clinical feature in diagnosing appendicitis.