Population Growth Alternative Assessment

Learn about population growth & carrying capacity with Paramecium! Assess your knowledge.

1. Name Type your name in the box below 2-3. Background Information The genus Paramecium consists of unicellular species of protists that live in freshwater environments. Under ideal conditions- sufficient food, water, and space, populations of these species grow rapidly and follow a pattern known as exponential growth. Exponential growth is explosive population growth in which the total number of potentially reproducing organisms increases with each generation. However, populations of organisms will not increase in size forever. Eventually, limitations of food, water, and other resources will cause the population to stop increasing. 2. Which factor below does not contribute to ideal growth conditions? Food Water Money Space 3. Use the reading to fill in the blank Exponential growth results in the total number of potentially reproducing organisms increases with each generation. More Background Information When a population arrives at the point where its size remains stable, it has reached the carrying capacity of the environment. The carrying capacity is the greatest number of individuals a given population can sustain. Competition for resources among members of a population (called intraspecific competition-we discuss this later) places limits on population size. 4. Fill in the blank Carrying capacity has been reached when the population has met the greatest number of individuals that can be supported by the environment. 5-6. Paramecium Growth Procedures-use these directions to answer the 2 questions below Begin the experiment by filling the test tubes with samples from the stock cultures in the flasks. (Click the bulb at the top of the pipette to fill the pipette with culture. Then click and drag the pipette to a test tube.) The first test tube will be filled with Paramecium caudatum, the secondtest tube will be filled with Paramecium aurelia, and the third will be filled with a combination of both Paramecium caudatum and Paramecium aurelia.*Note: there is rice in the test tubes. The rice is food for bacteria, which in turn will be food for the Paramecium. The two species of Paramecium do not prey upon each other.Next, prepare a wet-­‐mount slide from each of the test tubes. View each wet-­‐mount slide under the microscope. Count the number of cells of each type of Paramecium and record the data in the table provided. 5. Fill in the blank What is the independent variable from the experiment? type of paramecium 6. Fill in the blank What is the dependent variable of the experiment? number of cells 7-10. Use Graph 1 to answer questions 7. Fill in the blank On what day did the Paramecium caudatum population reach the carrying capacity of the environment when it was grown alone? (number only) 8 8. Fill in the blank On what day did the Paramecium aurelia population reach the carrying capacity, after overshooting, of the environment when it was grown alone? (number only) 12 9. Which type of paramecium produced the smallest number of cells during the 16 day time period? Paramecium aurelia Paramecium caudalum Paramecium aurelia, grown in mixed culture Paramecium caudalum, grown in mixed culture 10. Which strain of paramecium grew the best alone and in a mixed culture? Paramecium aurella Paramecium caudatum Paramecium alone Paramecium mixed culture 11. Using the graph above, which paramecium demonstrates the greatest exponential growth? A B C D Use the graph to answer questions 12-13 12. Which strand of paramecium produced the lowest population as of day 24? P. aurella separately P. aurella, in mixed population P. caudatum,separately P. caudatum, in mixed population 13. Fill in the blank On which day did both P. caudatumstrains produce the same number of cells?(number only) 7 Use the picture below to answer question 14 14. Fill in the blank Using the picture above, which strain of paramecium was most success after 16 days? (spelling counts) P. aurella Use the diagram below to answer question 15 15. Using the diagram above, which strain displayed the largest exponential growth from day 2 to day 4? A B C NONE