Which of the following units is equivalent to a joule?
- A. Newton-meter (N·m)
- B. Watt (W)
- C. Kilogram (kg)
- D. Ampere (A)
Correct Answer: A
Rationale: A joule is the SI unit of energy and work, defined as the work done by a force of one newton acting over a distance of one meter. Therefore, a joule is equivalent to a newton-meter (N·m), which represents the product of force (newton) and distance (meter). This unit reflects the energy transferred when a force of one newton moves an object one meter. Choice B, Watt (W), is the unit of power and is not equivalent to a joule. Choice C, Kilogram (kg), is a unit of mass. Choice D, Ampere (A), is the unit of electric current.
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Which hormone, produced by the pancreas, acts in opposition to insulin by increasing blood sugar levels?
- A. Insulin
- B. Glucagon
- C. Cortisol
- D. Thyroxine
Correct Answer: B
Rationale: Glucagon is the correct answer. Produced by the pancreas, glucagon acts in opposition to insulin by increasing blood sugar levels. Glucagon promotes the breakdown of glycogen into glucose in the liver, leading to the release of glucose into the bloodstream. Insulin, on the other hand, lowers blood sugar levels by facilitating the uptake of glucose into cells. Cortisol is a hormone produced by the adrenal glands, not the pancreas, and is involved in stress response and metabolism. Thyroxine is a hormone produced by the thyroid gland and is primarily responsible for regulating metabolism.
Which enzyme breaks down carbohydrates like starches and sugars in the mouth?
- A. Pepsin
- B. Lipase
- C. Amylase
- D. Trypsin
Correct Answer: C
Rationale: The correct answer is Amylase. Amylase is the enzyme responsible for breaking down carbohydrates like starches and sugars in the mouth. Pepsin is a digestive enzyme that breaks down proteins in the stomach, lipase breaks down fats, and trypsin is another enzyme that breaks down proteins in the small intestine. Therefore, choices A, B, and D are incorrect for this question.
What is the name of the growth plates in children's bones where new bone tissue is formed?
- A. Epiphyses
- B. Diaphysis
- C. Periosteum
- D. Medullary cavity
Correct Answer: A
Rationale: The correct answer is A: Epiphyses. Epiphyses are cartilaginous areas found at the ends of long bones, enabling growth and bone lengthening during childhood and adolescence. The diaphysis refers to the main shaft of a long bone. The periosteum is the outer bone layer responsible for nourishment and aiding in bone repair. The medullary cavity is the central cavity within the diaphysis that contains bone marrow but is not involved in new bone tissue formation.
What factors can contribute to edema, a condition characterized by swelling due to a buildup of lymph fluid?
- A. Regular exercise
- B. Maintaining a healthy weight
- C. Poor circulation or blockage in the lymphatic system
- D. Proper hydration
Correct Answer: C
Rationale: Edema is caused by the accumulation of excess fluid in the body's tissues, leading to swelling. Poor circulation or blockage in the lymphatic system can contribute to the development of edema by impairing the body's ability to properly drain fluid. While regular exercise, maintaining a healthy weight, and proper hydration are crucial for overall health, they are not direct causes of edema. Poor circulation or blockage in the lymphatic system disrupts the normal balance of fluid in the body, resulting in edema. Therefore, the correct factor that can contribute to edema is poor circulation or blockage in the lymphatic system.
Which neurotransmitter is associated with pleasure, reward, and motivation, and is often implicated in conditions such as addiction?
- A. Acetylcholine
- B. Dopamine
- C. Serotonin
- D. GABA (Gamma-aminobutyric acid)
Correct Answer: B
Rationale: Dopamine is the neurotransmitter associated with pleasure, reward, and motivation. It plays a crucial role in the brain's reward system and is often implicated in conditions such as addiction. Acetylcholine is involved in muscle movement and memory, serotonin is linked to mood regulation, and GABA is an inhibitory neurotransmitter that helps reduce neuronal excitability. Therefore, the correct answer is dopamine as it aligns with the neurotransmitter functions related to pleasure, reward, and motivation, distinct from the roles of acetylcholine, serotonin, and GABA.