1. Day 1: Ecological Interactions Homework due by Tuesday 4/24/18
TEKS
12A- interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms
12C- analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids
11C- summarize the role of microorganisms in both maintaining and disrupting the health of both organisms and ecosystems
12B- compare variations and adaptations of organisms in different ecosystems
Word Bank
Trophic Level
Food Chain
Food Web
Ecological Pyramid
Ecosystem
Predation
Parasitism
Commensalism
Mutualism
Competition
Producer
Consumer
____Predation______________________ When one organism consumes another organism
2. ___________________________________ A graphical representation of trophic levels in an ecosystem
3. ___________________________________ A relationship in which both species benefit
4. ___________________________________ The place an organism is in a food chain
5. ___________________________________ An organism that obtains nutrients from eating other organisms
6. ___________________________________ A relationship in which one organism harms another
7. ___________________________________ All biotic and abiotic factors in an area
8. ______ Food Web ____________________ A collection of food chains representing an entire ecosystem
9. ___________________________________ A relationship in which one organism benefits and the other is neither helped nor harmed
10. _________________________________ An organism that obtains energy from its surroundings
11. ____ Competition_________________ A relationship in which organisms are competing for the same resources
12. _________________________________ A diagram of relationships describing the transfer of energy from organism to organism

2. Food Chains/ Food Webs 12C (R)
1) Make a food chain in the space below
____________  ____________  ____________  _____________
2) What do the arrows in the food chain represent? __________________________________
3) Using the food web below, label Decomposers, Producers, Primary Consumers, Secondary Consumers, and Tertiary Consumers.
4) What could bacteria be classified as besides a decomposer?
5) What are other examples of decomposers?
6) What are other examples of producers besides plant species and bacteria?

3. Ecological Relationships 12A (R) Variations in Ecosystems 12B (S)
1) Provide a brief description of each type of symbiotic relationship.
Mutualism
Commensalism
Predation
Parasitism
Competition (Intraspecific)
Competition (Interspecific)
2) Read the scenario and determine which type of symbiotic relationship is being described.
____________________ 1. A tapeworm living in a 9th grade student’s intestines.
____________________ 2. A bird building a nest in a tree.
____________________ 3. The hermit crab carrying the sea anemone on its back for camouflage.
____________________ 4. Head lice living on a human scalp.
____________________ 5. Mistletoe putting its roots into its host tree taking its nutrients.
____________________ 6. The ants and the acacia tree living together and both receiving benefit.
____________________ 7. Orchids growing in tall tropical trees. The trees are not harmed but the orchids get sunlight.
____________________ 8. Two jaguars in the same area of the forest with limited prey species.
____________________ 9. Nitrogen-fixing bacteria living in root nodules of plants.
____________________ 10. Bees and a flower.
____________________ 11. Bacteria living safely in the intestines of a cow to help it break down cellulose.
____________________ 12. A lion catching and eating a gazelle.
Variations in Ecosystems 12B (S)
Looking at the pictures of the feet below, predict what type of environment the animals live in and how they move. (Terrestrial, aquatic, both)
What process led to the differences and foot type?

4. Ecological Pyramids 12C (R)
1) Label each trophic level on the ecological pyramid below and include examples of an organism found within each level.
2) What happens to the number of organisms in each trophic level as you go up towards the top of the pyramid?
3) How much energy is transferred as you move up one level?
4) Where does the remainder of the energy go?
5) Describe the difference between and energy pyramid and a biomass pyramid.
Role of Microorganisms in Ecosystems 11C (S)
1) Helpful or Harmful? Microorganisms such as bacteria and fungi can either support the health of an ecosystem or disrupt the ecosystem. Read each of the statements below and circle helpful or harmful.
Harmful / Helpful Nitrogen-fixing bacteria in root nodules convert nitrogen into a useable form.
Harmful / Helpful E. coli bacteria within our digestive system helps to break down food we eat.
Harmful / Helpful Food was not properly handled and cause food-poisoning.
Harmful / Helpful Strep throat is caused by the bacteria Streptococcus.
Harmful / Helpful Bacteria and fungi acts as decomposers recycling ecosystem nutrients.
Harmful / Helpful Bacteria can be used for bioremediation, such as cleaning up oil spills.
Harmful / Helpful Naturally occurring bacteria on your skin limit the growth of pathogenic bacteria.