Advanced Science: Diffusion And Osmosis Quiz (2nd Trimester, 2014-2015)

20 Questions | Total Attempts: 203

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Advanced Science: Diffusion And Osmosis Quiz (2nd Trimester, 2014-2015)

Questions and Answers
  • 1. 
    Diffusion is the net movement of molecules from an area of ______________________ concentration to an area of ___________________ concentration.* (Place a comma to separate your two answers).
  • 2. 
    • A. 

      Aquaporins

    • B. 

      Apertures

    • C. 

      Orofices

    • D. 

      Water channels

  • 3. 
    Once molecules reach a dynamic equilibrium on either side of a membrane they stop moving.
    • A. 

      True

    • B. 

      False

  • 4. 
    The thing that drives the diffusion of molecules are molecular collisions.
    • A. 

      True

    • B. 

      False

  • 5. 
    The brownish/orange circle is a cell and the white ring represents its membrane.  In which picture (A, B, or C) shows a hypertonic solution inside the cell, compared to a hypotonic solution outside the cell?  (Note: the green "dots" represent salt molecules). 
  • 6. 
    The brownish/orange circle is a cell and the white ring represents its membrane.  In which picture (A, B, or C) shows a isotonic solution inside and outside of the cell?  (Note: the green "dots" represent salt molecules). 
  • 7. 
    You eat spaghetti for dinner and digest the starch in it to glucose.  The glucose is now in high concentration in the cells of your small intestine, relative to its concentration in your bloodstream.  Predictably, the glucose diffuses across the cell membrane of the cells lining your small intestine and into the bloodstream.
    • A. 

      True, because diffusion moves molecules from a high to low concentration.

    • B. 

      False, because molecules cannot move across membranes by diffusion.

    • C. 

      False, because diffusion moves molecules from a low to high concentration.

    • D. 

      False, because molecules such as sugar are too large to move across cell membranes.

    • E. 

      False, because energy is required for diffusion.

  • 8. 
    Molecules are often said to: "move in constant random motion".  Why do molecules appear to move that way?  Choose the best answer.
    • A. 

      Because molecules have kinetic energy.

    • B. 

      Because molecules have potential energy.

    • C. 

      Because molecules are constantly colliding with each other.

    • D. 

      Because they move randomly due to the laws of physics.

  • 9. 
    What are "free" water molecules?
    • A. 

      Water molecules that don't require energy to move across cell membranes.

    • B. 

      Water molecules that are not bound to solutes (such as salt).

    • C. 

      Water molecules that are bound to salt molecules.

    • D. 

      Water molecules that are not connected to each other.

  • 10. 
    Molecular motion stops when:
    • A. 

      Collisions stop occurring.

    • B. 

      When two solutions become isotonic.

    • C. 

      All of the molecules have moved from high to low concentration.

    • D. 

      Molecules never stop moving. (Unless they reach absolute zero, and even this state is open to debate).

  • 11. 
    What term means the concentrations of a molecule are equal on both sides of a membrane?
    • A. 

      A.) Hypertonic

    • B. 

      B.) Hypotonic

    • C. 

      C.) Isotonic

    • D. 

      D.) Dynamic equilibrium

    • E. 

      Both "C" and "D' are correct

  • 12. 
    A molecule can move from low to high concentration.
    • A. 

      True

    • B. 

      False

  • 13. 
    Water molecules have a net movement from an area of lower solute concentration to an area of high solute concentration.
    • A. 

      True

    • B. 

      False

  • 14. 
    What term describes a membrane that allows some substances to pass through and prevents other substances from passing across it.
    • A. 

      Selectively permeable

    • B. 

      Permeable

    • C. 

      Impermeable

    • D. 

      Special barrier

  • 15. 
    Slugs die when salted.  Pick the best explanation for this action:
    • A. 

      Salt damages the slug's cells.

    • B. 

      A higher solute (salt) concentration on the outside of the slug creates a concentration gradient where water moves out of the slug rapidly, causing the slug's cells to rapidly dehydrate.

    • C. 

      A higher solvent (water) concentration on the outside of the slug causes a concentration gradient when water moves into the slug rapidly, causing the slug's cells to burst.

    • D. 

      Salt enters the slug's cells and pushes water out of the slug, causing it to dehydrate.

  • 16. 
    Which answer best explains why the Gummy Bears from our lab were larger the next day, after being placed in distilled water?
    • A. 

      Salt entered by osmosis from an area of high to lower concentration.

    • B. 

      Gummy bears often eat sugar during the day and grow overnight.

    • C. 

      A concentration gradient moved water from an area of low to higher concentration.

    • D. 

      Water entered the bears by osmosis from an area of high to lower concentration.

  • 17. 
    Osmosis is a type of diffusion.
    • A. 

      True

    • B. 

      False

  • 18. 
    After completing the "Gummy Bear Lab", a student noticed that their bear had changed color from a dark green to almost colorless.  Which answer best explains this observation?
    • A. 

      Water breaks down the green dye/pigment used to color the bear.

    • B. 

      The green dye/pigment diffused from an area of high to an area of lower concentration.

    • C. 

      As water moved into the bear, it pushed the green dye/pigment out.

    • D. 

      Green gummy bears possess chlorophyll for photosynthesis... this chlorophyll breaks down rapidly in the presence of water.

  • 19. 
    Diffusion stops if there is no concentration gradient.
    • A. 

      True

    • B. 

      False

  • 20. 
    If an animal cell was placed in a hypertonic solution, which answer best predicts what would happen?
    • A. 

      The cell will shrivel and possibly die due to loss of water by osmosis.

    • B. 

      The cell will expand and possibly die due to the gain of water by osmosis.

    • C. 

      The cell will shrivel and possibly die due to loss of salt by diffusion.

    • D. 

      The cell will expand and possibly die due to the gain of salt by diffusion.