Which of the following is a unit of work and energy?

Correct Answer: B

Rationale: The correct answer is 'B: Kilowatt-hour (kWh).' The kilowatt-hour is a unit commonly used to measure electricity consumption, representing energy usage over time. A Pascal (Pa) is a unit of pressure, Coulomb (C) is a unit of electric charge, and Tesla (T) is a unit of magnetic flux density. Therefore, the kilowatt-hour is the appropriate unit for measuring work and energy in this context.

Correct Answer: A

Rationale: The main function of the stomach is to store food, churn it, and break it down into smaller pieces through mechanical digestion. This process is facilitated by the mixing of food with gastric juices, including stomach acid. The mechanical breakdown in the stomach helps initiate the digestion of food before it progresses to the small intestine for further digestion and nutrient absorption. Absorption of nutrients into the bloodstream primarily occurs in the small intestine, not the stomach. Enzymes that aid in digesting food are primarily produced in the pancreas and small intestine, not in the stomach. The elimination of waste products from the body mainly occurs through the large intestine and rectum, not the stomach.

Correct Answer: A

Rationale: The main function of the kidneys is to filter waste products, excess ions, and water from the bloodstream to form urine, which is then excreted from the body. This process helps maintain the body's internal environment by regulating the balance of electrolytes, fluid volume, and pH levels. While the kidneys do produce urine as a result of filtering the blood, their primary function is to filter waste products rather than solely producing urine. Although the kidneys play a role in regulating blood pressure by controlling blood volume and electrolyte concentration, their main function is waste filtration. While the kidneys do produce hormones like erythropoietin and renin that regulate physiological processes, such as red blood cell production and blood pressure, the main role of the kidneys is waste filtration.

Correct Answer: B

Rationale: The amplitude of a wave determines the loudness of sound when heard by the human ear. The greater the amplitude of a sound wave, the louder the sound will be perceived. Frequency (Choice A) refers to the number of wave cycles in a given time period. Wavelength (Choice C) is the distance between two corresponding points on a wave. Velocity (Choice D) is the speed at which the wave travels and does not directly affect the loudness of sound perceived by the human ear.

Correct Answer: C

Rationale: A) Fluid drainage from tissues: This function is attributed to the lymphatic system. Lymphatic vessels collect excess fluid from tissues and return it to the bloodstream. B) Immune response via white blood cell production: The lymphatic system plays a crucial role in the body's immune response by producing and transporting white blood cells, such as lymphocytes, which help fight infections. C) Nutrient transport throughout the body: Nutrient transport is primarily carried out by the circulatory system (blood vessels), not the lymphatic system. The circulatory system transports nutrients, oxygen, and hormones to cells and removes waste products. D) Waste removal through lymph nodes: The lymphatic system helps remove waste and toxins from the body by filtering lymph through lymph nodes, where harmful substances are trapped and destroyed by immune cells. Therefore, the function NOT attributed to the lymphatic system is C) Nutrient transport throughout the body.