Nokea
What is the primary function of the cardiovascular system?
- A. To transport oxygen and nutrients
- B. To remove waste products
- C. To regulate body temperature
- D. To fight infections
Correct Answer: A
Rationale: The correct answer is A: "To transport oxygen and nutrients." The primary function of the cardiovascular system is to transport oxygen, nutrients, and hormones to cells throughout the body and remove waste products. This system plays a crucial role in maintaining homeostasis by delivering essential substances to tissues and organs while eliminating metabolic waste. Choices B, C, and D are incorrect because although the cardiovascular system indirectly helps in removing waste products through circulation, its primary function is focused on transporting essential substances and not on regulating body temperature or fighting infections.
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What is the primary function of the respiratory system?
- A. To remove carbon dioxide from the body
- B. To transport oxygen to the cells
- C. To deliver nutrients to cells
- D. To create sound and speech
Correct Answer: B
Rationale: The primary function of the respiratory system is to facilitate the exchange of gases. It transports oxygen from the air into the bloodstream, which is crucial for cellular respiration and providing energy to the cells. Additionally, it removes carbon dioxide, which is a waste product that needs to be eliminated. Choices A, C, and D are incorrect because while the respiratory system does remove carbon dioxide, its primary role is oxygen transport, not nutrient delivery, sound, or speech production.
Which vitamin is necessary for the absorption of calcium?
- A. Vitamin C
- B. Vitamin D
- C. Vitamin A
- D. Vitamin K
Correct Answer: B
Rationale: Vitamin D is the correct answer. It is essential for the absorption of calcium in the intestines, facilitating the maintenance of strong bones and teeth. Vitamin D helps regulate calcium levels in the blood and promotes bone mineralization, making it crucial for overall bone health. Choices A, C, and D are incorrect because Vitamin C is not directly involved in calcium absorption, Vitamin A is more related to vision and immune function, and Vitamin K plays a role in blood clotting and bone mineralization but is not primarily responsible for calcium absorption.
Which gland produces melatonin?
- A. Pineal gland
- B. Thyroid gland
- C. Adrenal gland
- D. Pituitary gland
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.
What is the primary function of the kidneys in the urinary system?
- A. To filter waste from the blood
- B. To produce urine
- C. To regulate blood pressure
- D. To absorb nutrients
Correct Answer: A
Rationale: The correct answer is A: 'To filter waste from the blood.' The primary function of the kidneys in the urinary system is to filter waste products and excess substances from the blood, forming urine, which is then excreted from the body. Kidneys play a crucial role in maintaining the body's overall balance by filtering out waste, regulating fluid levels, and helping in the elimination of toxins. Choices B, C, and D are incorrect because while the kidneys do produce urine, regulate blood pressure, and help in nutrient absorption indirectly, their primary function is the filtration of waste from the blood.
What is the primary function of the integumentary system?
- A. Protecting the body from external damage
- B. Regulating body temperature
- C. Producing vitamin D
- D. Producing red blood cells
Correct Answer: A
Rationale: The correct answer is A: Protecting the body from external damage. The primary function of the integumentary system, which includes the skin, hair, and nails, is to act as a physical barrier that protects the body from external damage such as pathogens, UV radiation, and mechanical injuries. While the integumentary system does play roles in regulating body temperature and producing vitamin D, its main and most crucial function is to provide a protective shield for the body. Choices B, C, and D are incorrect because although the integumentary system contributes to regulating body temperature and producing vitamin D, as well as housing cells involved in the immune response, its primary role is protection.