Which of the following describes the process of osmosis?
- A. Diffusion of solutes across a membrane
- B. Movement of water across a selectively permeable membrane
- C. Movement of gases across a membrane
- D. Active transport of ions across a membrane
Correct Answer: B
Rationale: Osmosis is the process where water molecules move across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration. This movement of water helps to equalize the concentration of solutes on both sides of the membrane. The correct description of osmosis is the movement of water across a selectively permeable membrane, making choice B the right answer. Choices A, C, and D are incorrect because osmosis specifically refers to the movement of water molecules, not solutes, gases, or ions across a membrane.
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What type of joint is found in the shoulder?
- A. Ball and socket joint
- B. Hinge joint
- C. Saddle joint
- D. Pivot joint
Correct Answer: A
Rationale: The correct answer is a ball and socket joint. The shoulder joint is a ball and socket joint, allowing for a wide range of motion, including rotation. This joint provides excellent flexibility and mobility, making movements like circular motions and rotations possible. A hinge joint, like the elbow, allows movement in only one plane (flexion and extension). A saddle joint, found in the thumb, allows for a wide range of motion but not as much as a ball and socket joint. A pivot joint, such as the joint between the first and second vertebrae of the neck, allows rotation only.
Which type of muscle tissue is under voluntary control?
- A. Smooth muscle
- B. Cardiac muscle
- C. Skeletal muscle
- D. Cardiac muscle
Correct Answer: C
Rationale: Skeletal muscle is under voluntary control, allowing conscious regulation for activities like walking and lifting. This type of muscle is attached to bones and is responsible for movement in the body. Smooth muscle (Choice A) is involuntary and found in organs like the stomach and intestines. Cardiac muscle (Choice B and D) is also involuntary and specific to the heart, contracting rhythmically to pump blood, but it is not under conscious control.
Which vitamin is necessary for the formation of collagen?
- A. Vitamin A
- B. Vitamin C
- C. Vitamin D
- D. Vitamin E
Correct Answer: B
Rationale: Vitamin C is essential for the synthesis of collagen, a crucial protein that plays a significant role in maintaining the structural integrity of skin, blood vessels, and bones. Collagen is responsible for the strength, elasticity, and firmness of these tissues. Without sufficient vitamin C, the body cannot form collagen properly, leading to various health issues like scurvy, impaired wound healing, and fragile blood vessels. Choices A, C, and D are incorrect. Vitamin A plays a role in vision, immune function, and skin health. Vitamin D is crucial for bone health and immune function, while Vitamin E is an antioxidant that helps protect cells from damage.
What type of tissue forms the outer layer of the skin?
- A. Connective tissue
- B. Epithelial tissue
- C. Muscle tissue
- D. Nervous tissue
Correct Answer: B
Rationale: Epithelial tissue is the correct answer. It forms the outer layer of the skin, serving as a protective barrier against pathogens and environmental damage. This tissue type is essential for maintaining skin integrity and plays a crucial role in skin function. Connective tissue (Choice A), although important for providing support and structure, does not form the outer layer of the skin. Muscle tissue (Choice C) is responsible for movement and is not the primary tissue in the skin. Nervous tissue (Choice D) is involved in transmitting signals but is not the main component of the skin's outer layer.
Which hormone is released by the pancreas to lower blood glucose levels?
- A. Insulin
- B. Glucagon
- C. Cortisol
- D. Somatostatin
Correct Answer: A
Rationale: Insulin is the hormone released by the pancreas to lower blood glucose levels. Insulin facilitates the uptake of glucose into cells, helping to decrease blood glucose levels and store excess glucose for energy or future use. Glucagon, on the other hand, raises blood glucose levels by promoting the breakdown of glycogen into glucose. Cortisol and somatostatin do not directly regulate blood glucose levels in the same manner as insulin and glucagon.