Download Work sheet for assignment 6

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.