Correct Answer: C

Rationale: The correct answer is C: Testes. The testes are responsible for producing testosterone, the hormone that plays a crucial role in male secondary sexual characteristics such as facial hair, deepening of the voice, and muscle development. The adrenal glands primarily produce cortisol and aldosterone, not testosterone. The pituitary gland regulates hormone production in various glands, including the testes, but it does not directly produce testosterone. The pancreas is responsible for producing insulin and glucagon to regulate blood sugar levels, not testosterone.

Correct Answer: B

Rationale: The correct answer is B: To transport oxygen. Red blood cells play a crucial role in carrying oxygen from the lungs to all the tissues and organs in the body. This oxygen transport is essential for cellular respiration, where oxygen is used in the production of energy. Red blood cells do not primarily transport nutrients, fight infection, or produce antibodies. Choice A is incorrect because while red blood cells do carry some nutrients, their primary function is to transport oxygen. Choice C is incorrect because immune cells, not red blood cells, are responsible for fighting infections. Choice D is incorrect as antibody production is mainly carried out by specialized white blood cells, not red blood cells.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver plays a crucial role in detoxifying chemicals and metabolizing drugs. It also produces bile for digestion. The liver contains enzymes that help metabolize drugs and toxins, making them easier for the body to eliminate. The kidneys are primarily responsible for filtering blood and regulating fluid balance, the heart's main function is to pump blood, and the pancreas produces digestive enzymes and hormones like insulin, but they do not have the primary function of detoxifying chemicals and metabolizing drugs.

Correct Answer: C

Rationale: Power is the rate at which work is done or energy is transferred. The unit of measurement for power is the watt (W), named after James Watt, the inventor of the steam engine. The watt is defined as one joule per second, where a joule (J) is the unit of energy. Choice A, Joule (J), is incorrect because a joule is a unit of energy, not power. Choice B, Newton (N), is incorrect as a Newton is a unit of force, not power. Choice D, Kilogram-meter (kg·m), is incorrect as it represents a unit of torque, not power. Therefore, the correct answer is C: Watt (W).

Correct Answer: C

Rationale: The correct answer is C: 'To regulate body functions through hormones.' The endocrine system is responsible for producing and secreting hormones that help regulate various body functions such as growth, metabolism, reproduction, and mood. It does not primarily function to fight infection (A), transport oxygen (B), or break down food (D). While the immune system fights infection, the respiratory system transports oxygen, and the digestive system breaks down food, the main role of the endocrine system is to maintain homeostasis by coordinating and controlling bodily functions through the release of hormones.