Nokea
Which vitamin is produced when the skin is exposed to sunlight?
- A. Vitamin A
- B. Vitamin D
- C. Vitamin K
- D. Vitamin E
Correct Answer: B
Rationale: Vitamin D is the correct answer. When the skin is exposed to sunlight, it triggers a process where a form of cholesterol in the skin is converted into vitamin D. This vitamin plays a crucial role in aiding calcium absorption in the gut, which is essential for maintaining strong and healthy bones. Vitamin A (Choice A) is important for vision and immune function but is not produced by sunlight exposure. Vitamin K (Choice C) is known for its role in blood clotting and bone metabolism, but it is not produced by sunlight. Vitamin E (Choice D) is an antioxidant that protects cells from damage but is not synthesized in the skin through sunlight exposure.
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Which of the following is a function of the large intestine?
- A. Absorption of water
- B. Production of vitamin K
- C. Production of vitamin B
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D, 'All of the above.' The large intestine performs various functions, including the absorption of water, production of vitamin K, and production of some B vitamins. Water absorption is a crucial function of the large intestine, helping to concentrate waste material into feces. Additionally, the large intestine hosts beneficial bacteria that produce vitamin K and some B vitamins, which are absorbed into the body. Choices A, B, and C individually represent specific functions of the large intestine, while choice D correctly encompasses all these functions, making it the most comprehensive and accurate answer.
Which structure in the lungs is the site of gas exchange?
- A. Trachea
- B. Alveoli
- C. Bronchioles
- D. Diaphragm
Correct Answer: B
Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from inhaled air diffuses into the bloodstream, while carbon dioxide from the blood is released into the alveoli to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs, but it is not involved in gas exchange. Bronchioles (Choice C) are small air passages within the lungs that branch off from the bronchi, leading air to the alveoli but not directly involved in gas exchange. The diaphragm (Choice D) is a muscle below the lungs that helps in breathing by expanding and contracting the chest cavity, but it is not the site of gas exchange.
What is the function of the lymphatic system?
- A. To transport oxygen
- B. To filter waste from the blood
- C. To produce red blood cells
- D. To regulate body temperature
Correct Answer: B
Rationale: The correct answer is B: 'To filter waste from the blood.' The lymphatic system is responsible for draining excess fluid from tissues, absorbing fats from the digestive system, and filtering out harmful substances and waste products from the blood. It also plays a crucial role in the body's immune defense by transporting white blood cells and antibodies to fight off infections. Choices A, C, and D are incorrect because transporting oxygen, producing red blood cells, and regulating body temperature are functions performed by other systems in the body, such as the respiratory system, bone marrow, and thermoregulatory mechanisms, respectively.
Which of the following is a genetic condition that affects the respiratory system?
- A. Asthma
- B. Cystic fibrosis
- C. Mycosis
- D. Surfactant Deficiency
Correct Answer: B
Rationale: The correct answer is B, Cystic fibrosis. Cystic fibrosis is a genetic disorder that primarily affects the respiratory and digestive systems. It leads to the production of thick mucus in the lungs, causing breathing difficulties and increasing the risk of respiratory infections. Choice A, Asthma, is a chronic respiratory condition characterized by inflammation and narrowing of the airways, but it is not a genetic condition. Choice C, Mycosis, refers to fungal infections and is not a genetic condition specifically affecting the respiratory system. Choice D, Surfactant Deficiency, is a condition related to respiratory distress syndrome in newborns and is not a genetic disorder affecting the respiratory system in general.
What is the primary function of white blood cells?
- A. To carry oxygen
- B. To fight infection
- C. To transport nutrients
- D. To transport waste
Correct Answer: B
Rationale: The correct answer is B: "To fight infection." White blood cells are primarily responsible for fighting infections and foreign invaders in the body, making them a critical component of the immune system. Choice A, "To carry oxygen," is incorrect as red blood cells are responsible for oxygen transport. Choice C, "To transport nutrients," is incorrect as this function is mainly attributed to blood plasma and other specialized cells. Choice D, "To transport waste," is also incorrect as waste removal is primarily handled by the kidneys and the lymphatic system, not white blood cells.