Assignment 6 Ecology Due July 11 1. Essay (4 points) Using the organisms in the sponge community, describe two food chains. Each chain must have at least three organisms in it--when describing your chain, start with the lowest trophic level. One of your food chains must include the sponge. 2. Essay (2 points) Convert your food chains in question 1 into a food web by adding at least one primary or secondary consumer. Explain how your food web differs from the food chains. 3. Multiple select (3 points) Pick three of the following members of the sponge community that are most likely to be primary consumers: ___ tunicate ___ barnacle ___ flatworm ___ fire worm ___ brittlestar ___ nudibranch ___ crab ___ sponge 4. Multiple select (3 points) Pick three of the following members of the sponge community that are most likely to be secondary consumers: ___ tunicate ___ barnacle ___ burrowing annelid predator ___ burrowing annelid filter-feeder ___ tube-dwelling crustacean ___ parasitic annelid ___ fan worm ___ sponge 5. Multiple select (3 points) Pick three of the following members of the sponge community that are most likely to be tertiary consumers: ___ small crustaceans, like the isopod ___ fan worm ___ crab ___ borrowing annelid filter-feeder ___ nudibranch ___ tunicate ___ cnidarian ___ sponge 6. Multiple-choice (1 point) Which group of animals in the sponge community (if any) can be placed at all three consumer levels? brittlestar crab flatworm tunicate none of these 7. Essay (3 points) Study this terrestrial food web and pick one animal that is a primary consumer, one that is a secondary consumer, and one that is a tertiary consumer. Explain each of your answers. 8. Multiple-choice (1 point) Where should the two protists shown in videos be placed in the energy producers primary consumers only secondary consumers only primary and secondary consumers secondary and tertiary consumers 9. According to the article on rare bacteria discovered in an ocean census, how many bacterial "species" are thought to inhabit the ocean (although most of them have not yet been identified)? about 20,000 about 100,000 about 1 million no more than 5 million at least 10 million 10. Multiple-choice (1 point) According to the article on rare bacteria, which new tool(s) are responsible for the rapid identification of different types of bacteria in marine environments? a new molecular technique for analyzing large amounts of mitochondrial DNA a new molecular technique that requires only tiny pieces of DNA a new, more powerful type of microscope a more sophisticated method for collecting bacteria all of these 11. Multiple-choice (1 point) Examine the ecoplates in the experiment on bacterial diversity in soil. Which soil sample contains the greatest diversity of bacteria based on their use of carbon sources? bacteria collected in the grassy area were more diverse bacteria collected under the tree were more diverse there is no difference in diversity between the two soil samples the control was positive in one soil sample, so comparisons are invalid there is no way to make this type of comparison 12. File upload (3 points) Use the table below determine how much overlap there is in bacterial species from the two soil samples. Put an X in every well where the bacteria from grass consumed the nutrient and a Z in wells where the bacteria from beneath the tree consumed the nutrient. A1 A2 A3 A4 B1 B2 B3 B4 C1 C2 C3 C4 D1 D2 D3 D4 E1 E2 E3 E4 F1 F2 F3 F4 G1 G2 G3 G4 H1 H2 H3 H4 Do a screen capture of the filled-out table and submit it to WebAssign as a jpg or png image for question 12. 13. Fill-in-the-blank (2 points) Now count the number of wells in your table that contain both an X and a Z and divide by the total number of positive wells (containing one or two letters). Convert your result to a percent (multiple by 100) and round it to the closest whole number. The percent of overlap in nutrient use by the two bacterial samples is ______ %. 14. Essay (2 points) Where would you place heterotrophic bacteria in your energy pyramid for sponge communities? Explain your answer.