Lesson Plan

Ecosystem Interactions

Grade Levels

10th Grade, 11th Grade, 12th Grade

Course, Subject

Environment and Ecology,Biology



Biotic Factor- living components of ecosystems
Abiotic Factor- non-living components of ecosystems
Symbiosis- a relationship where 2 organisms live in close association with each other
Predation- a relationship between 2 organisms where one organism, the predator, feeds on the other organism or prey (+,-)
Predator- a consumer that feeds on other consumers
Prey- the organism that is eaten by the predator
Parasitism- a relationship between 2 organisms where one organism, the parasite, feeds off of the host (+,-)
Host- the organism the parasite lives in or on
Parasite- an organism that feeds off of another living organism
Mutualism- a relationship that exists between 2 organisms where both benefit (+,+)
Commensalism- a relationship that exists between 2 organisms where one organism benefits and the other is unchanged (+,0)
Competition- a relationship between 2 organisms who use the same resources (+,-)


The students will be able to…

1. Identify both abiotic and biotic factors and describe their interactions within ecosystems.

2. Use + (benefits), - (harms), and 0 (no change) symbols to correctly identify given symbiotic relationships that occur in ecosystems.

3. Read information sheets on given symbiotic relationships, evaluate the type of relationship, and report out to their small group.

4. Compile a chart with at least 3 examples of each symbiotic relationship presented in class.

Lesson Essential Question(s)

How do organisms interact and depend on each other and their environment for survival?


1- 85 minute class periods


Symbiosis Power Point (with multiple examples)
Information sheets with descriptions of symbiotic relationships.
Table Response cards with the words: mutualism, commensalism, parasitism, competition, predation

Suggested Instructional Strategies

W= Post the standard and the agenda on the board
H= Use real pictures of organisms, also use examples that directly affect each student like “mites living in eyebrows” and “bacteria living in the human intestine”, also interject the effect of antibiotics on the good bacteria in the digestive system
E= Jigsaw activity
R= Rehearse with response cards
E= Jigsaw chart, response cards in closure will allow the students to self-assess their own understanding of the symbiotic relationships
T= Create a handout with more examples, teacher observation and redirection
O= This lesson contains a variety of teacher directed as well as student directed activities with numerous “real-life” examples

Instructional Procedures

  1. Written Bell ringer- Using your knowledge of root words, write as much as you know about abiotic and biotic factors in your journals. Discuss answers. (Independent, Whole Group) [5 min]
  2. Show a photograph of a typical ecosystem on the IWB. Have the students list as many abiotic and biotic factors as they possibly can from the picture. (Independent) [5 min]
  3. Use the random reporter strategy to generate an exhaustive list of abiotic and biotic factors found in the example ecosystem picture. What Biome is represented in this picture? (Whole Group) [5 min]
  4. Special relationships also occur between organisms in ecosystems. Have the students fill out the guided note sheet while the teacher presents a few examples of symbiotic relationships. Make sure to include one example and photograph of each of the following relationships in the notes: mutualism, commensalism, competition, predation, and parasitism. (Whole Group) [15 min]
  5. Jigsaw activity: Randomly distribute a short fact sheet describing one symbiotic relationship to each student. Have each student read the information sheet individually. While reading the information sheet, they should record the type of symbiotic relationship and apply the symbols for each relationship. For example a tick on a dog is an example of parasitism. This is a +, - relationship because the tick (parasite) benefits while the dog (host) is harmed. When all students are done, they will form expert groups and compare answers. Regroup the students so that each expert group is represented in the non-expert groups. Have the students report to their group and complete the guided note sheet. At the completion of this activity every student will have at least one more example of each symbiotic relationship. (Small Group, Independent) [40 min]
  6. Closure: Distribute the pre-made response cards with “mutualism”, “commensalism”, “parasitism”, “competition”, and “predation” written on each card. Students will work individually to determine the symbiotic relationships presented by teacher and will show the appropriate response card when prompted. (Independent) [10 min]

Formative Assessment

Bell ringer
Guided note
Peer group Jigsaw Activity
Response cards

Related Materials & Resources

Symbiosis Pictures or Posters


Date Published

March 28, 2011
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