Unit-II Molecular Transport in Living SystemBy abdulslambsn@gmail.com / May 16, 2025 Quiz 2 | Unit II Molecular Transport in Living System Your Good Name: Your College Name: Morning/Evening/Private: Email: 1. What is Brownian motion? Motion of a particle in a straight line Motion of particles in a crystal lattice Random motion of particles in a fluid Motion of particles in a vacuum None 2. In Brownian motion, what type of friction dominates the motion of particles? Viscous Friction Static Friction Kinetic Friction Rolling Friction None 3. Which of the following is NOT a factor affecting the magnitude of Brownian motion? Temperature Particle size Fluid density Particle charge None 4. What is the diffusion coefficient? A measure of a particle's mass A measure of a particle's size A measure of a particle's velocity A measure of how fast particles spread out None 5. Fick's law is primarily used to determine: The rate of diffusion of a substance The temperature of a substance The concentration gradient of a substance The pressure of a substance None 6. According to Fick's law, the rate of diffusion is directly proportional to: The concentration gradient The temperature The pressure The viscosity None 7. Which factor affects the rate of diffusion according to Fick's law? Surface area Temperature Thickness of the membrane All of the above None 8. What does Fick's law predict about the movement of particles in a concentration gradient? Particles move from high concentration to low concentration Particles remain stationary Particles move from low concentration to high concentration Particles move randomly None 9. What is the fundamental concept underlying membrane potential? Movement of ions across a membrane Osmotic pressure across a membrane Electrical resistance of a membrane Diffusion of molecules through a membrane None 10. What does the Nernst equation calculate? Membrane capacitance Membrane permeability Membrane potential Rate of diffusion None 11. Which ion primarily contributes to the resting membrane potential in neurons? Sodium (Na+) Potassium (K+) Calcium (Ca2+) Chloride (Cl-) None 12. What effect does increasing membrane permeability to potassium ions have on resting membrane potential? Decreases it No effect Increases it Depends on the concentration gradient None 13. What is the typical resting membrane potential of a neuron? -70 mV +40 mV 0 mV -90 mV None 14. The movement of ions such as sodium and potassium across the cell membrane against their concentration gradients is primarily facilitated by: Simple Diffusion Osmosis Active Transport Facilitated Diffusion None 15. Which of the following transport mechanisms requires a concentration gradient? Osmosis Facilitated Diffusion Active Transport Both A and B None 16. In which transport mechanism do molecules move from an area of lower concentration to an area of higher concentration? Osmosis Facilitated diffusion Simple diffusion Active transport None 17. Active transport is often involved in: Maintaining osmotic balance Regulating cell size Facilitating gas exchange None of the above None 18. Which of the following is a characteristic of passive transport? Requires energy input Moves substances against the concentration gradient Occurs without the need for transport proteins Requires specific carrier proteins or channels None 19. Which of the following is an example of facilitated diffusion? Movement of oxygen through the lipid bilayer Movement of water through aquaporins Movement of glucose through GLUT transporters Movement of ions through ion channels None 20. Which of the following is NOT an example of active transport? Sodium-Potassium Pump Endocytosis Exocytosis Glucose transport via GLUT proteins None 21. Which of the following best describes diffusion? Movement of molecules from low to high concentration Movement of molecules requiring energy Movement of molecules from high to low concentration Movement of water only None 22. The sodium-potassium pump moves: 2 Na+ out, 3 K+ in 2 Na+ in, 3 K+ out 3 Na+ out, 2 K+ in 3 Na+ in, 2 K+ out None 23. Which equation accounts for multiple ion species in calculating membrane potential? Nernst equation Goldman-Hodgkin-Katz equation Michaelis-Menten equation Fick's law None 24. The primary purpose of the sodium-potassium pump is to: Generate ATP Facilitate diffusion Maintain ion concentration gradients Create action potentials None 25. Which ion has a higher concentration inside the cell compared to outside? Sodium (Na+) Potassium (K+) Calcium (Ca2+) Chloride (Cl-) None 1 out of 3 Thanks For Submitting Your Quiz !!