Quizzes: Lab-related

1. An environmental change causes the contractile vacuole of a paracemium to stop functioning, while most of the other cell structures appear to be unaffected. Which environmental change would most likely produce this result?
temperature change from 20 degrees centigrade to 25 degrees centigrade
pH change from 7.0 to 6.5
large decrease in the amount of light
slight increase in salt concentration of the environment

2. A student is studying the internal structures of an earthworm. To examine a cross-section of the portion of the earthworm's digestive tract that is specialized for mechanical digestion, the student should
observe the ventral side of the crop with a compound light microscope
make a longitudinal cut through the mouth and view the result with a dissecting microscope
make a vertical cut through the gizzard and view the result with a dissecting microscope
observe a thin section of the intestine with a compound light microscope

3. A student added 10 mL of a yeast suspension and 10 mL of 30 degrees centrigrade water to each of two test tubes. FIve grams of sugar was then added to one of the test tubes. Both test tubes were generally swirled to mix the contents, and then the test tubes were placed in a warm water bath for 15 minutes. The student made observations of any bubbles that formed in the test tubes and recorded the data in a table. This experiment was most likely carried out to investigate the
effect of sugar on metabolic activity of yeast
effect of temperature on a specific metabolic activity of yeast
solubility of sugar in a yeast suspension
solubility of sugar used in a metabolic pathway of ATP formation

4. When a fish opens and closes its mouth, water is forced over the gills, which act as teh sties of gas exchange. Four teams of students investigated the effect of temperature on the rate of mouth openings in a certain species of fish. Proper experimental procedure was followed throughout the investigation. What will most likely happen to the rate of respiration in this species of fish if the temperature is constantly being decreased.
Due to temperature's effect on the solubility of gases, the fish will have to open its mouth more often to receive more oxygen.
Due to temperature's effect on the solubility of gases, the fish will have to open its mouth less.
Due to temperature's effect on enzymes, the fish will be unable to open and close its mouth so rapidly at lower temperatures.
Due to temperature's effect on enzymes, the fish will be able to decrease the time intervals between each opening and closing of its mouth.

5. A single protist was placed in a large test tube containing nutrient broth. The tube was then kept at room temperature for 24 hours. Samples of respiration from the tube were taken periodically during the 24 hours using a respirometer. Which graph best represents what is happening in the tube in the evolutionary terms of successful species?


Graph 1
Graph 2
Graph 3
Graph 4

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Correct answers: