Nokea
Which type of blood cell is responsible for carrying oxygen?
- A. Red blood cells
- B. White blood cells
- C. Platelets
- D. Plasma cells
Correct Answer: A
Rationale: The correct answer is A: Red blood cells. Red blood cells, also known as erythrocytes, are specialized cells designed to transport oxygen from the lungs to tissues and organs throughout the body. These cells contain hemoglobin, a protein that binds to oxygen molecules in the lungs and releases them in other parts of the body where oxygen is needed for cellular respiration. White blood cells (choice B) are part of the immune system, responsible for fighting infections. Platelets (choice C) are involved in blood clotting. Plasma cells (choice D) are a type of white blood cell that produces antibodies to help the body fight off infections.
You may also like to solve these questions
Which type of muscle tissue is found in the heart?
- A. Smooth muscle
- B. Cardiac muscle
- C. Skeletal muscle
- D. Striated muscle
Correct Answer: B
Rationale: Cardiac muscle tissue, represented by choice B, is the correct answer. Cardiac muscle tissue is unique to the heart and responsible for its involuntary contractions that pump blood throughout the body. Smooth muscle (choice A) is found in the walls of hollow organs, skeletal muscle (choice C) is attached to bones for movement, and striated muscle (choice D) is a general term that can refer to both cardiac and skeletal muscle but is not specific to the heart.
Which of the following structures regulates the transport of substances in and out of a cell?
- A. Nucleus
- B. Cell membrane
- C. Cytoplasm
- D. Mitochondria
Correct Answer: B
Rationale: The cell membrane, also known as the plasma membrane, is responsible for regulating the transport of substances in and out of the cell. It acts as a selective barrier, allowing the passage of certain molecules while restricting others. This selective permeability helps maintain homeostasis within the cell by controlling the movement of essential substances like nutrients and waste products. The nucleus (Choice A) is the organelle that houses the cell's genetic material and is not directly involved in regulating substance transport. Cytoplasm (Choice C) is the gel-like substance that fills the cell and does not play a direct role in regulating substance transport. Mitochondria (Choice D) are responsible for energy production in the cell through cellular respiration and are not primarily involved in substance transport.
What is the most visible part of the ear?
- A. Pinna
- B. Organ of Corti
- C. Cochlea
- D. Ear canal
Correct Answer: A
Rationale: The pinna, also known as the auricle, is the external part of the ear that is most visible. It helps in collecting sound waves and directing them into the ear canal for further processing by the ear structures. The pinna's visible location makes it easily identifiable as the prominent external feature of the ear. Choices B, C, and D are incorrect. The Organ of Corti is located within the cochlea and is responsible for converting sound vibrations into electrical signals. The cochlea is a spiral-shaped, fluid-filled structure in the inner ear that plays a crucial role in hearing. The ear canal is a passage that leads to the eardrum and is not the most visible part of the ear.
Which vitamin is essential for calcium absorption?
- A. Vitamin A
- B. Vitamin D
- C. Vitamin K
- D. Vitamin C
Correct Answer: B
Rationale: Vitamin D is crucial for the absorption of calcium in the intestines. It aids in maintaining optimal calcium levels in the body, promoting strong bones and teeth. Without sufficient Vitamin D, the absorption of calcium can be compromised, leading to potential issues with bone health. Choices A, C, and D are incorrect. Vitamin A is essential for vision, skin health, and immune function. Vitamin K is necessary for blood clotting and bone metabolism. Vitamin C is important for collagen synthesis, wound healing, and immune function, but it is not directly involved in calcium absorption.
What is the function of the kidneys in the urinary system?
- A. To filter blood and remove waste
- B. To produce red blood cells
- C. To regulate blood pressure
- D. To absorb water
Correct Answer: A
Rationale: The correct answer is A: 'To filter blood and remove waste.' The kidneys play a crucial role in the urinary system by filtering blood to remove waste products and excess fluids, which are then excreted as urine. This process helps maintain the body's internal balance by regulating electrolyte levels and controlling blood pressure. Choices B, C, and D are incorrect because the kidneys do not produce red blood cells (bone marrow does), regulate blood pressure directly (although they indirectly influence it through the renin-angiotensin-aldosterone system), or absorb water (they regulate water balance but do not absorb water).