Nokea
Where are B-lymphocytes produced?
- A. Thymus
- B. Red bone marrow
- C. Lymph nodes
- D. Spleen
Correct Answer: B
Rationale: B-lymphocytes are produced in the red bone marrow. The red bone marrow is the primary site for B-cell development, where they mature before entering the circulation. The thymus is responsible for T-lymphocyte maturation, not B-lymphocytes. Lymph nodes and spleen play roles in immune responses but are not the primary sites for B-lymphocyte production.
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Which muscle is responsible for the extension of the elbow?
- A. Biceps brachii
- B. Triceps brachii
- C. Deltoid
- D. Pectoralis major
Correct Answer: B
Rationale: The correct answer is B: Triceps brachii. The triceps brachii muscle is responsible for extending the elbow joint. It is located on the back of the upper arm and acts in opposition to the biceps brachii, which is responsible for elbow flexion. The deltoid muscle is primarily responsible for shoulder abduction, not elbow extension. The pectoralis major muscle is involved in movements of the shoulder joint, not the elbow.
What is the primary function of the pancreas in digestion?
- A. To absorb nutrients
- B. To secrete digestive enzymes
- C. To produce bile
- D. To store glucose
Correct Answer: B
Rationale: The correct answer is B: To secrete digestive enzymes. The pancreas plays a crucial role in digestion by secreting digestive enzymes that break down carbohydrates, fats, and proteins in the small intestine. These enzymes help in the process of breaking down food particles into smaller molecules that can be easily absorbed by the body for nutrients. Choices A, C, and D are incorrect as the primary function of the pancreas is not to absorb nutrients, produce bile, or store glucose in digestion.
Which organelle in the cell is responsible for packaging and distributing proteins?
- A. Ribosome
- B. Golgi apparatus
- C. Endoplasmic reticulum
- D. Mitochondrion
Correct Answer: B
Rationale: The Golgi apparatus is an organelle responsible for packaging and distributing proteins and lipids within the cell. It modifies, sorts, and packages these molecules into vesicles for transportation to their final destinations, either within the cell or outside of it. The Golgi apparatus plays a crucial role in the secretory pathway of cells, ensuring that proteins are properly processed and directed to where they are needed. Ribosomes are responsible for protein synthesis, not packaging and distributing proteins. The endoplasmic reticulum is involved in protein synthesis and folding but not primarily in packaging and distributing proteins. Mitochondria are known as the powerhouse of the cell and are responsible for generating energy in the form of ATP through cellular respiration, not packaging and distributing proteins.
Which vitamin is essential for the synthesis of collagen?
- A. Vitamin C
- B. Vitamin D
- C. Vitamin B12
- D. Vitamin K
Correct Answer: A
Rationale: The correct answer is Vitamin C. Vitamin C is essential for the synthesis of collagen, a protein crucial for maintaining the structure and integrity of skin, blood vessels, and bones. It plays a key role in the hydroxylation of proline and lysine residues in collagen synthesis, which is necessary for the stability and strength of collagen fibers.
Choice B: Vitamin D is essential for bone health and calcium absorption but is not directly involved in collagen synthesis.
Choice C: Vitamin B12 is important for red blood cell formation and neurological function but is not directly related to collagen synthesis.
Choice D: Vitamin K is necessary for blood clotting and bone metabolism but does not play a direct role in collagen synthesis.
What is the primary function of the kidneys in the urinary system?
- A. Regulating blood pressure
- B. Filtering blood to remove waste
- C. Producing red blood cells
- D. Regulating electrolyte balance
Correct Answer: B
Rationale: The primary function of the kidneys in the urinary system is to filter blood to remove waste products and excess fluids, which are then excreted as urine. Kidneys act as a filtration system, removing waste like urea, excess salts, and toxins. While the kidneys do play a role in regulating blood pressure by secreting renin and maintaining electrolyte balance by adjusting the levels of sodium, potassium, and other ions in the blood, their main and essential function is filtration and waste removal, making choice B the correct answer.