Gr.7 "Food Chains" & Energy Transfer-H.S.Concept Presentation
Presenter: Leonard Monticolo
Instructors: J. Extavour & M. Zatzman
Mentor: Feras Suleiman
Date: July 21st, 2010
Background Information:
Where Does This Concept Go in Grade 7?
1)
Within the Gr.7 “Ecosystems” Unit
Rationale:
- after concepts such as “basic needs of all living organisms” and “biotic versus abiotic” have
been taught/reviewed
2)
The "Ecosystems" Unit should be the 1st unit of the year
Rationale:
- most students have a decent amount of background knowledge/schema from previous years so
they’re usually more comfortable with the topic
- in autumn, it's a lot easier to make observations and collect samples on field trips!
- very few safety considerations (besides hygiene and a respect for nature!) so...
the teacher can focus on learning more about the ways his/her students function on their own, in
pairs and in groups (assessment "as" learning;)
How Does This Fit in Within the Big Picture of K-12 Science in Ontario?
Before Gr.7:
Within the "Understanding Life Systems" Strand:
• Gr.1 - Needs and Characteristics of Living Things
• Gr.2 - Growth and Changes in Animals
• Gr.3 - Growth and Changes in Plants
• Gr.4 - Habitats and Communities
• Gr.6 - Biodiversity
After Gr.7:
• Biology Gr.9 (Academic & Applied) - Sustainable Ecosystems & Human Activity
• Biology Gr.11 (University) - Diversity of Living Things
• Biology Gr.12 (University) - Population Dynamics
• Env. Sci. Gr.11 (U/C) - Sci. Solutions to Contemporary Env. Challenges
- Sustainable Agriculture & Forestry
• Env. Sci. Gr.11 (Work) - Human Impact on the Environment
- Natural Resource Sci. & Managrment
Curriculum Expectations Related to this Concept:
Grade 7 Understanding Life Systems-Interactions in the Environment
Big Ideas:
•Ecosystems are made up of biotic (living) and abiotic (non-living) elements, which depend on
each other to survive.
•Ecosystems are in a constant state of change. The changes may be caused by nature or by
human intervention.
•Human activities have the potential to alter the environment. Humans must be aware of these
impacts and try to control them.
Overall Expectations:
1. assess the impacts of human activities and technologies on the environment, and evaluate
ways of controlling these impacts
2. investigate interactions within the environment, and identify factors that affect the balance
between different components of an ecosystem
3. demonstrate an understanding of interactions between and among biotic and abiotic elements
in the environment
Specific Expectations:
2. Developing Skills of Scientific Investigation & Technological Problem Solving
2.1 follow established safety procedures for investigating ecosystems
2.3 use scientific inquiry/research skills to investigate occurrences that affect the balance within a
local ecosystem
2.4 use appropriate science and technology vocabulary, including sustainability, biotic,
ecosystem, community, population, and producer, in oral and written communication
2.5 use a variety of forms to communicate with different audiences and for a variety of purposes
3. Understanding Basic Concepts
3.1 demonstrate an understanding of an ecosystem as a system of interactions between living
organisms and their environment
3.3 describe the roles and interactions of producers, consumers, and decomposers within an
ecosystem
3.4 describe the transfer of energy in a food chain & explain the effects of the elimination of any
part it
3.5 describe how matter is cycled within the environment and explain how it promotes
sustainability
3.7 explain why an ecosystem is limited in the number of living things that it can support
3.8 describe ways in which human activities and technologies alter balances and interactions in
the environment
Practical Applications and Societal Implications
• Human activities and technologies have the potential to (and usually do) alter the environment!!!
• How do we control/minimize these impacts???
• Here's a recent example (amongst thousands) you might have heard of BP Gulf Oil Spill:(
Learning Difficulties/Misconceptions & Possible Solutions
Learning Difficulty #1:
• students think plants get their food from the soil & air (i.e. water, minerals & oxygen)
Possible Solution:
• review the process of photosynthesis using visual aids and online demos
Learning Difficulty #2:
• students have a hard time grasping that plants are the producers in any food chain because
they make their own food and, as a result, energy only enters the chain through them
Possible Solution:
• review the basic differences between plants and animals and explore various food chains
through the use of interactive software (i.e. smartboard food chain activity)
• "...the plant must be seen as the transformer of solar energy into a chemical that it stores in
itself. In this manner, the flow of energy through food chain members would be understood, as
would the role of the plant as producer and beginner of the food chain." (Gallegos et al., 1994)
Learning Difficulty #3:
• students easily grasp that higher trophic levels depend on lower trophic levels (i.e. the survival
of owls depends on mice populations) but find it much more difficult to understand that lower
levels depend on higher levels (i.e. if owls are removed, mice suffer overpopulation)
Possible Solution:
• shared reading of books like "Wolf Island" by Celia Godkin and NGM article "Wolf Wars" with
discussion groups focussed on why top predators are needed in any food web
• online activities such as "Crocodile Food Chain" or "Rat Attack" from Nova Website
Learning Difficulty #4:
• students often misinterpret arrows in food webs, thinking they indicate the direction of predation,
instead of energy flow, so they think the arrows point the wrong way and draw them in the wrong
direction as a result
Possible Solution:
• explore various examples of food webs and have them work through their own food web
diagrams as practice (they need to understand that only plants produce energy and thus energy
flows away from plants through consumers)
Learning Difficulty #5:
• students tend to think of food chains as a clean, linear progression from producer to consumers
rather than multi-directional
Possible Solution:
• have students participate in various food web games ("String" Web activity, Andrew's "Food
Chain" Activity or "Trophic Web Cocktail Party")
Lesson Outline (with a focus on D.I. and A & E)
Lesson #1: Introducing Topic and Preparation for Field Trip (40 min)
• begin with "Fast Food Chain" video and think/pair/share
• next, class discussion and KWL Chart ("for" learning)
• then, have students fill out either "Word Anticipation Guide" or "Word Development Guide"
(ESL/ELL get this one along with glossary of terms sheet)
-due 1st class back after trip ("for" learning)
•after that, discuss nature and purpose of next class' field trip, show them what the activity sheet
will look like and discuss what is expected of them & review safety considerations
•Exit Pass:"3,2,1" on trip related items ("as" learning)
D.I./M.I.- tailored to audio/visual, interpersonal, intrapersonal and linguistic learners
(kinesthetic learners will just have to hang in there!)
Lesson #2: Field Trip to Exciting Neighbourhood Locations!!! (1/2 Day)
• begin with review of what is to be accomplished by end of each "location"
• next, class taken to various local habitats (school field, ravine close by, wooded area in park,
overgrown field under hydro towers, etc.)
• then, have students fill out field trip activity sheet with partners and take digital photos of choice
items to discuss next class (teacher and/or students taking photos)
-due 1st class back after trip ("for" learning)
•after that, discuss (after a think/pair/share) what their overall impressions were at each location
before heading back to school ("for" learning)
D.I./M.I.- tailored to visual, interpersonal, naturalistic and yes!...kinesthetic learners
(musical learners can sing as we walk from place to place;)
Lesson #3: Producers V.S. Consumers - Intro to Food Chains (40 min)
• begin with a word wall game and collect sheets from 1st class and trip
• next, create group/class sketches of habitats visited to post around room ("for" learning)
• then, have students work either alone or in pairs (especially for ESL/ELL) on "Producers or
Consumers" Reading Activity ("as" & "for" learning)
• after that, finish with Smart Board Activity on Food Chains ("for" learning)
D.I./M.I.- tailored to visual, interpersonal, intrapersonal, kinesthetic and linguistic learners
Lesson #4: Food Webs (40 min)
• begin with "Wolf Island" Story and discussion (“as” learning)
• next, share article from NGM March 2010 titled "Wolf Wars" and have students create
Before/After chart regarding Yellowstone Habitat Changes to be handed in by the end of class
("for" learning)
• then, assign computer lab activity from Nova Website for students to complete at home and
bring in next day to discuss ("for" learning)
D.I./M.I.- tailored to visual, interpersonal, intrapersonal, logical and linguistic learners
Lesson #5: Food Webs Continued (40 min)
• begin with sharing of results from online activity ("as" learning)
• next, go through "String" Web Activity with class and then think/pair/share ("for" learning)
• then, demo food web & pyramid illustrations and have students complete their own then share
their results with their group("as" & "for" learning)
D.I./M.I.- tailored to visual, interpersonal, intrapersonal, kinesthetic and logical learners
Lesson #6: Food Webs Continued (40 min)
• begin with "Trophic Web Party" activity (kiddie version!) (ESL/ELL need to be paired up with
someone that is more proficient in english) and then think/pair/share ("for" learning)
• next, give out quiz on food web diagram ("of" learning)
D.I./M.I.- tailored to visual, interpersonal, intrapersonal, kinesthetic, linguistic, and finally musical
learners!!!
Annotated References
1) Barker, Kyn et al. Science & Technology 7. Addison Wesley, Canada. (1999)
(a decent text to be used as a resource only as it was published during "old"
curriculum)
2) Chadwick, D.H. Wolf Wars. National Geographic Magazine. (March 2010 Issue)
(really worth getting a subscription because there are always great, topical photos)
3) Gallegos, L. et al. Preconceptions and Relations Used by Children in the Construction of Food
Chains. Journal of Research in Science Teaching. Vol.31, No.3, pp.259-272 (1994)
(An interesting bit of research with helpful notes on misconceptions)
4) Godkin, C. Wolf Island. Fitzhenry & Whiteside. Markham, Canada. (1989)
(a story you should have if you teach ecology!-teacher's guide free online
through publisher)
5) Ontario Ministry of Education and Training. (2007) The Ontario Curriculum, Grades 1-8
Science & Technology (Revised).
(if you need this one annotated, you're in trouble;)
6) Ontario Ministry of Education and Training. (200?) Think Literacy!
(a great resource if you're feeling the "Literacy" Pressure;)