Correct Answer: A

Rationale: The correct answer is the Pineal gland. This gland is responsible for producing melatonin, a hormone that helps regulate the sleep-wake cycle. Melatonin production is influenced by exposure to light, with levels typically rising in the evening to promote sleep and falling in the morning to aid wakefulness. The Thyroid gland (choice B) produces hormones that regulate metabolism, the Adrenal gland (choice C) produces hormones like adrenaline and cortisol, and the Pituitary gland (choice D) controls several other glands in the endocrine system.

Correct Answer: B

Rationale: The correct answer is B: Remove carbon dioxide from the body. The primary function of the lymphatic system is to return excess tissue fluid to the bloodstream and assist in the body's defense against infections by filtering out harmful pathogens and foreign particles. Choices A, C, and D are incorrect because transporting oxygen to cells is mainly done by the circulatory system, hormone production is primarily carried out by endocrine glands, and nutrient transport is also a function of the circulatory system and the digestive system, not the lymphatic system.

Correct Answer: B

Rationale: Neuroglia are specialized connective tissue cells that provide support and protection to neurons in the nervous system. They assist in the proper functioning of neurons and are essential for maintaining the overall health of nerve tissue. Therefore, in the context of nerve tissue composition, neuroglia are the connective tissue cells associated with neurons. The other choices, osteoblasts, osteocytes, and arterioles, are not the correct types of connective tissue cells found in nerve tissue. Osteoblasts are involved in bone formation, osteocytes are mature bone cells, and arterioles are small blood vessels that supply blood to tissues.

Correct Answer: B

Rationale: The adrenal glands function to produce hormones such as adrenaline and cortisol. These hormones play essential roles in regulating metabolism, immune response, and the body's response to stress. Therefore, the correct answer is that the adrenal glands produce hormones. Choices A, C, and D are incorrect as regulating blood sugar is primarily done by the pancreas, producing red blood cells is the function of the bone marrow, and filtering blood is carried out by the kidneys, not the adrenal glands.

Correct Answer: B

Rationale: The circulatory system's primary function is to transport oxygen, nutrients, and hormones to cells and remove waste products. Choice A is incorrect because hormone production is primarily carried out by endocrine glands. Choice C is incorrect as fighting infections is a role of the immune system. Choice D is incorrect as regulating body temperature is mainly controlled by the integumentary and nervous systems.