Nokea
What is the role of surfactant in the respiratory system?
- A. To trap dust particles
- B. To increase lung compliance
- C. To produce mucus
- D. To generate oxygen during respiration
Correct Answer: B
Rationale: The correct answer is B: To increase lung compliance. Surfactant is a substance produced by type II alveolar cells in the lungs that reduces surface tension in the alveoli. This reduction in surface tension helps to increase lung compliance, making it easier for the lungs to expand and contract during breathing. Improved lung compliance is essential for efficient gas exchange in the respiratory system, facilitating oxygen uptake and carbon dioxide removal. Choices A, C, and D are incorrect because surfactant does not trap dust particles, produce mucus, or generate oxygen during respiration. Instead, its primary function lies in reducing surface tension to prevent alveolar collapse and improve lung compliance for optimal gas exchange.
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What is the process of removing waste products from the cell called?
- A. Exocytosis
- B. Endocytosis
- C. Phagocytosis
- D. Pinocytosis
Correct Answer: A
Rationale: A) Exocytosis is the process by which cells expel waste products or other substances by fusing a vesicle containing the waste with the cell membrane, releasing its contents outside the cell. This process is essential for maintaining cellular homeostasis by removing waste products from the cell.
B) Endocytosis is the process by which cells take in substances by engulfing them in a vesicle formed from the cell membrane. This process is the opposite of exocytosis and is used to bring substances into the cell.
C) Phagocytosis is a type of endocytosis where cells engulf solid particles or other cells to form a vesicle called a phagosome. This process is used by immune cells to engulf and destroy pathogens.
D) Pinocytosis is a type of endocytosis where cells engulf fluids and dissolved solutes. This process allows cells to take in nutrients.
Why is the electrical conductivity of a strong acid solution higher than that of a weak acid solution?
- A. Strong acids are more concentrated.
- B. Strong acids release more hydrogen ions.
- C. Weak acids are better at dissolving salts.
- D. Strong acids have a lower pH.
Correct Answer: B
Rationale: The correct answer is B because strong acids release more hydrogen ions compared to weak acids. This higher concentration of ions in the solution leads to a higher electrical conductivity. Strong acids ionize completely in solution, producing a higher concentration of ions that can conduct electricity, whereas weak acids only partially ionize, resulting in a lower concentration of ions and lower electrical conductivity. Choice A is incorrect because the concentration of the acid does not directly determine its electrical conductivity. Choice C is incorrect as the ability to dissolve salts is not directly related to electrical conductivity. Choice D is incorrect because the pH of the solution, although related to acidity, does not directly determine the electrical conductivity.
What is the term for the distance between the center of a lens or curved mirror and its focal point?
- A. Aperture
- B. Focal length
- C. Refractive index
- D. Lens thickness
Correct Answer: B
Rationale: The correct answer is B: Focal length. Focal length is the distance between the center of a lens or curved mirror and its focal point. It determines how strongly the lens converges or diverges light, affecting the image formation. Aperture, choice A, refers to the opening through which light enters the lens, controlling the amount of light passing through. Refractive index, choice C, measures how much light bends when passing through a medium, affecting the speed of light. Lens thickness, choice D, is the physical dimension of the lens, influencing optical properties and compatibility with frames.
What is the study of fungi known as?
- A. Virology
- B. Mycology
- C. Bacteriology
- D. Parasitology
Correct Answer: B
Rationale: Mycology is the correct answer. Mycology is the branch of biology that specifically deals with the study of fungi. Fungi constitute a separate kingdom of organisms that include various forms such as yeasts, molds, and mushrooms. Virology (A) is the study of viruses, while Bacteriology (C) focuses on bacteria. Parasitology (D) is the study of parasites, which may include protozoa, helminths, and some fungi, but it is not solely dedicated to fungi.
Which element is used in fire extinguishers to smother flames by displacing oxygen?
- A. Nitrogen
- B. Carbon dioxide
- C. Helium
- D. Argon
Correct Answer: B
Rationale: Carbon dioxide is the correct answer. It is used in fire extinguishers because it displaces oxygen, which is necessary for combustion. When carbon dioxide is released onto a fire, it reduces the oxygen concentration around the flames, effectively smothering the fire. This disruption of oxygen availability interrupts the chemical reaction that sustains the fire. Nitrogen (Choice A), helium (Choice C), and argon (Choice D) are not typically used in fire extinguishers for smothering flames by displacing oxygen. Nitrogen is an inert gas that can displace oxygen but is not as effective as carbon dioxide in fire suppression.