Nokea
Which vitamin is essential for calcium absorption and bone health?
- A. Vitamin A
- B. Vitamin C
- C. Vitamin D
- D. Vitamin E
Correct Answer: C
Rationale: Vitamin D is essential for calcium absorption in the intestines, which is crucial for maintaining strong and healthy bones. Without adequate vitamin D, the body cannot effectively absorb calcium, leading to weakened bones and an increased risk of fractures. Vitamin A (Choice A) is important for vision and immune function but is not directly involved in calcium absorption or bone health. Vitamin C (Choice B) is essential for collagen synthesis and immune function, but it does not play a direct role in calcium absorption or bone health. Vitamin E (Choice D) acts as an antioxidant and helps protect cells from damage, but it is not specifically required for calcium absorption or bone health. Therefore, the correct answer is Vitamin D as it is crucial for optimal bone health.
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Which condition is characterized by inflammation of the inner lining of the stomach?
- A. Gastroesophageal reflux disease (GERD)
- B. Diverticulitis
- C. Ulcerative colitis
- D. Gastritis
Correct Answer: D
Rationale: Gastritis is the correct answer as it is characterized by inflammation of the inner lining of the stomach. This inflammation can be caused by various factors such as excessive alcohol consumption, prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs), infections, or autoimmune diseases. Symptoms of gastritis may include abdominal pain, nausea, vomiting, and loss of appetite. Gastroesophageal reflux disease (GERD) is incorrect because it involves the backflow of stomach acid into the esophagus, leading to symptoms like heartburn and regurgitation, not inflammation of the stomach lining. Diverticulitis refers to inflammation or infection of small pouches that can form in the walls of the colon, not the stomach. Ulcerative colitis is a type of inflammatory bowel disease characterized by inflammation and ulcers in the colon and rectum, not the stomach lining.
Which type of cell has a nucleus but lacks membrane-bound organelles?
- A. Plant cell
- B. Prokaryotic cell
- C. Animal cell
- D. Fungal cell
Correct Answer: B
Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus that is not enclosed within a membrane (nuclear envelope) and lacking membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant, animal, and fungal cells are eukaryotic cells, which have a true nucleus enclosed within a nuclear envelope and contain membrane-bound organelles. Therefore, options A, C, and D are incorrect as they all represent eukaryotic cells that possess membrane-bound organelles.
The lymphatic system is a network of vessels and organs that plays a vital role in:
- A. Transporting oxygen and nutrients to cells
- B. Carrying waste products away from tissues
- C. Regulating body temperature
- D. Producing red blood cells
Correct Answer: B
Rationale: The correct answer is B: Carrying waste products away from tissues. The lymphatic system functions to maintain fluid balance in the body by removing excess fluid, filtering out harmful substances, and transporting waste products away from tissues. It does not primarily focus on transporting oxygen and nutrients to cells, regulating body temperature, or producing red blood cells. Choices A, C, and D are incorrect as the primary function of the lymphatic system is related to waste removal and maintaining fluid balance in the body, rather than roles such as nutrient transport, temperature regulation, or red blood cell production.
Vacuoles are large sacs for storage in plant cells. What is their main function in animal cells?
- A. Protein synthesis
- B. Waste storage and disposal
- C. Photosynthesis
- D. Cellular respiration
Correct Answer: B
Rationale: Vacuoles in animal cells primarily function in waste storage and disposal, helping to maintain cellular homeostasis by storing waste products and aiding in their removal from the cell. Unlike plant cells, animal cells do not typically use vacuoles for storage purposes such as water, nutrients, or pigments. Instead, animal cells rely on other organelles like lysosomes for waste management and maintaining cellular balance. Choices A, C, and D are incorrect because protein synthesis occurs in ribosomes, photosynthesis takes place in chloroplasts (absent in animal cells), and cellular respiration mainly occurs in mitochondria, respectively. Vacuoles in animal cells serve a different purpose compared to plant cells.
The tonsils and adenoids are part of the lymphatic system located in the:
- A. Chest cavity
- B. Abdominal cavity
- C. Head and neck region
- D. Pelvic cavity
Correct Answer: C
Rationale: The tonsils and adenoids are lymphatic tissues located in the head and neck region, specifically in the throat area. They are essential components of the immune system, acting as the first line of defense against infections that can enter through the nose and mouth. The tonsils are situated at the back of the throat, while the adenoids are positioned high in the throat behind the nose. Choices A, B, and D are incorrect as they do not correspond to the anatomical location of the tonsils and adenoids. Therefore, the correct answer is the head and neck region.