Earth Science Exam 2 Review
Energy and Nutrient Flow in Ecosystems
Vocabulary to know:
 ecosystem
 biotic
 abiotic
 organism
 species
 population
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Diversity of Life:
1. Fill in the missing information from the table.
Cellular
Kingdom
organization
Archaeabacteria
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community
producers
consumers
decomposers
food chain
food web
Unicellular,
Prokaryotic
trophic level
energy pyramid
herbivore
carnivore
omnivore
heterotroph
 autotroph
 biogeochemical
cycle
Energy/Food
Examples
Where found
Most are autotrophic
Halophiles,
thermophiles,
acidophiles
Extreme
environments
Lactobacillus
Staphylococcus
Streptococcus
E. coli
Algae (plant
like);
Plasmodium
(animal like)
causes malaria
Eubacteria
Unicellular,
Prokaryotic
Heterotrophic
Some autotrophic
Protista
Most
unicellular;
Eukaryotic
animal-like = heterotrophs
plant-like = autotrophs
fungi-like = heterotrophs
Fungi
Unicellular
(mold, yeast)
Multicellular
(mushrooms);
Eukaryotic
Heterotrophs
yeast,
mushrooms,
mold
Everywhere
Plantae
Multicellular,
Eukaryotic
Autotrophs
Trees, grasses,
flowers,
vegetables, etc.
primarily
terrestrial
Animalia
Multicellular;
Eukaryotic
Heterotrophs
Insects, fish,
mammals, etc.
Everywhere
everywhere
Everywhere aquatic, terrestrial
2. To which kingdom do Plasmodia, the organisms which cause malaria, belong? Protista
3. Define halophiles, thermophiles, and acidophiles. Which kingdom includes all of these organisms? Halophiles –
“salt-loving” live in extremely salty environments; thermophiles – “heat-loving”; acidophiles – “acid-loving” All from
the Archaeabacteria kingdom
4. Which kingdom(s) are producers? Archaeabacteria, some Eubacteria, some Protista, Plantae
5. Which kingdom(s) only include prokaryotes? Archaeabacteria and Eubacteria
6. Which kingdom(s) are decomposers? Some Archaeabacteria, some Eubacteria, Fungi, Some Protista
Ecosystems:
7. What is the difference between a population and a community? A population is a group of the same species living in
an area, while a community includes all living organisms in an area
8. Distinguish between biotic and abiotic factors and give 3 examples of each in a pond ecosystem. Biotic – living or
once-living; abiotic – non-living: Biotic – frog, algae, bacteria, fish, cattails, etc. Abiotic – water, temperature,
salinity, pH, rocks, air, etc.
9. What is the difference between a community and an ecosystem? An ecosystem includes the abiotic factors in
addition to the biotic factors.
Energy Flow in Ecosystems:
10. For this energy pyramid, draw or write an organism for each level: producer, quaternary consumer, primary
consumer, tertiary consumer, and secondary consumer.
Bottom – producers (plants); next level up – primary (insect, for example); middle section – secondary (frog, for
example); next to top – tertiary (snake, for example); top level – quaternary (hawk, for example)
11. Fill in the amount of energy available to each level
Energy______0.56__________________
Energy _____5.6___________________
Energy____56 kJ_________________
Energy_____560___________________
Energy______5600__________________
12. Explain how producers and consumers influence each other.
Producers convert energy from sun into food (sugars) and oxygen, which is used by consumers; consumers in turn
give off carbon dioxide which producers use; in addition, decomposed consumers provide nutrients for producers
13. Give an example of each of the following in a forest ecosystem: herbivore, carnivore, omnivore, and decomposer
Examples: Herbivore – rabbit; carnivore – coyote; omnivore – turkey; decomposer - mushroom
14. Explain how a raccoon could be a primary consumer, a secondary consumer, and a tertiary consumer. (Raccoons are
omnivores.)
If a raccoon eats corn = primary; if it eats a chicken that ate corn = secondary; if it eats a chicken that ate a worm =
tertiary
15. How much of the energy from one trophic level is available to the next trophic level?
10%
16. Draw a food chain that includes at least 6 trophic levels and label each level as decomposer, primary consumer,
tertiary consumer, secondary consumer, producer, and quaternary consumer. Draw three more chains containing at
least 3 trophic levels and interconnect your chains. (You can write the names of the organisms, rather than draw, if
you choose.
(answers will vary)
Food Chain 1
Food Chain 2
Food Chain 3
Food Chain 4
17. What is your diagram now called? A food web
18. Identify one additional food chain with at least 5 levels – you may not include one of your original 4 chains.
(Answers will vary)
Biogeochemical Cycles:
19. Draw arrows showing the direction of the flow of carbon in the diagram below.
20. Explain how plants and animals rely on each other for carbon. What other product do plants provide animals?
Plants produce sugars (carbon compounds) which animals eat when the eat plants; animals in turn give off carbon
dioxide for plants to take in and produce sugars
21. How does carbon re-enter the carbon cycle after it becomes trapped in fossil fuels?
Burning fossil fuels
22. Identify one biotic and one geologic portion of the carbon cycle.
Plants or animals would be biotic; fossil fuels, atmospheric carbon dioxide would be abiotic
23. Draw arrows showing the direction of flow of nitrogen in the diagram below.
24. If plants and animals can’t utilize atmospheric nitrogen, by what process are they able to obtain the nitrogen
necessary to them?
Nitrogen fixing bacteria convert atmospheric nitrogen to nitrogen compounds that plants can use; animals get nitrogen
by eating plants and other animals which ate plants.
25. Farmers often rotate their corn crops with soybeans. Why do they choose soybeans and not some other type of
crop for this rotation?
Soybeans have nodules that contain nitrogen fixing bacteria; these bacteria replenish nutrients in soil
26. Identify one biotic and one geologic portion of the nitrogen cycle. Biotic = bacteria; plants or animals that
decompose; abiotic = atmospheric nitrogen
27. Draw arrows showing the direction of flow of phosphorus in the diagram below.
28. How do plants and animals rely on each other for phosphorus?
Plants take in phosphorus from soil, animals consume plants; animals decompose and return phosphorus to soil
29. Identify one biotic and one geologic portion of the phosphorus cycle.
Biotic = plants and animals; abiotic rocks that contain phosphorus
30. How do bacteria and fungi contribute to the phosphorus cycle?
Bacteria and fungi return phosphorus to soil be decomposing dead plants or animals