1. If the daphnia are dead, what could have happened to them?
    Glucose was put into the tank.
  2. What experiment would you use to test the hypothesis with the daphnia experiment?
    Benedict's test on cloudy water because glucose is a reducing sugar.
  3. If the hypothesis with the daphnia is supported, what can you conclude?
    Glucose killed the daphnia/
  4. Given
    that your hypothesis is supported, propose an explanation as to why the Daphnia
    died in terms of osmosis, diffusion, tonicity and the effects of
    hyper/hypo-tonic solutions on living cells.
    • Glucose
    • created a hypertonic solution. This
    • caused water to leave the cells of the daphnia by the process of osmosis,
    • thereby killing the daphnia (dehydration, electrolyte imbalance, etc.)
  5. What are the 4 steps of the scientific method?
    Observation, hypothesis, experiment, conclusion
  6. 1. You
    are walking through the woods when you discover a small twitching blob. You think it might be alive so you bring it
    to class. Unfortunately by the time you
    get to class, it is no longer twitching.
    Your instructor decides to let you dissect it. When you cut the blob open you see a round
    mass of tissue in the center of the blob so you cut into it. You make a slide from that tissue and look at
    it under the microscope. What you see is
    a confusing mass of cells. It appears as
    though the cells have branches. Within
    the cell body you see a single nucleus.
    What do you think this tissue/cell type might be? And what would its function be?
    Nerve cells, conduction of impulses
  7. You remove a piece of some very tough tissue of the twitching blob. Under the microscope you see linear strands of fibers that appear to have striations
    in them. You wonder what would happen if
    you applied an electric current to this tissue in the blob. Your instructor gets an electrode and applies
    a mild electric current. The tissue
    twitches! What type of tissue do you
    think this is? What is its function?
    Muscle cells, movement
  8. With
    all of this cutting, the blob begins to leak.
    You examine the fluid under the microscope and see many individual cells
    all with a nucleus. What type of cells
    do you think these are? Which other
    animal cell type do these cells resemble?
    Blood cells, they resemble frog red blood cells
  9. After examining the red liquid found in the doorway, you notice some tiny oval shaped structures. Each one has a purple dot in the center and rounder structures that are also stained purple. Is this human blood or something else?
    Frog blood
  10. For your pet dog, what would a Benedict's test be able to determine?
  11. For your pet dog, what would a Biuret's test be able to determine?
  12. For your pet dog, what would a water solubility test be able to determine?
  13. For your pet dog, what would an iodine test be able to determine?
  14. You return from a bathroom break during
    your lab class on diffusion and osmosis, having just drank half a bottle of
    water. You return to find that your
    water has been moved and your lab partners are looking your way, pointing to
    the bottle, and snickering. You then
    catch a glimpse of an empty salt packet on the table. Are your lab partners trying to be
    funny? How would you determine whether
    or not they had poured the salt in your water without drinking it?
    • Make a dialysis bag using the water from your
    • bottle and put it in a beaker of known fresh water. If the bag expands, there is probably salt in your water. You may also put your water in the beaker to see if the bag shrinks.
  15. Brownian movement is due to the random movement of _____ molecules.
  16. This experiment illustrated how ________ affects the rate of diffusion. Molecule _ diffused faster.
    A) Circle with little circle
    B) Circle with big circle

    This experiment demonstrated the effect of temperature
    on the rate of diffusion. The reaction
    occurred faster at (higher/lower) temperatures. Iodine diffused into the starch as seen by the dark blue
    color (inside/outside) of the bag. This happened because iodine has a smaller molecular size
    than starch.

    Temperature, higher, Iodine, starch, dark blue, inside, iodine, molecular size, starch
  17. Hypotonic outside of the bag means that (20% inside)
    the water moved into the cell
  18. No net movement of water in or out the bag means that
    the solution is isotonic
  19. Water outside of the cell means that the solution is (20% in, 60% out)
  20. On a graph, where would the curves of hypotonic, hypertonic and isotonic be located?
    Hypo on top, iso in the middle, hyper on the bottom
  21. An emulsion is a combination of two _____ liquids in which one fo the liquids is in the form of _____. This occurs with the aid of an ______ such as _______.
    Immiscible, droplets, emulsifier, detergent
  22. In which organelle of a potato cell would we find starch?
  23. When acid is added to whole milk, the milk _____. This happens because the proteins in the milk are ______.
    Curdles, denatured
  24. The breakdown of starch into maltose is accomplished by the process of _____ with the help of the enzyme ______ which is found in _____.
    hydrolysis, amylase, saliva
  25. We were able to see evidence of the breakdown of starch by adding _____ to the reaction. The color started out as ________ and got _____ as time elapsed.
    iodine, dark blue, lighter
  26. The optimum temperature for our enzyme
    was __ degrees Celsius.
  27. In general, as temperature increases,
    the rate of enzyme activity (increases/decreases)
    up to a certain point called the optimum temperature, at which activity is at a
    maximum. After this point, activity (increases/decreases). At very
    high temperatures we see (high/low/no)
    activity because the enzyme is
    increase, optimum, decreases, no, denatured
Card Set
Lab Exam 1