B2.5: Describe how matter is cycled within the environment, and explain how…
Describe how matter is cycled within the environment, and explain how the cycling of matter promotes sustainability. (decomposers and matter cycling; an early start on a Grade 7 expectation).
The Ontario Science and Technology, Grades 1–8 outcome B2.5 (Life Systems) for Grade 7 says: “Describe how matter is cycled within the environment, and explain how the cycling of matter promotes sustainability. (decomposers and matter cycling; an early start on a Grade 7 expectation).” This Fieldbook unit teaches it hands-on, with everyday materials and a printable teacher guide and student sheet for every lesson. Official wording: Ontario Science and Technology, Grades 1–8.
Food Webs: Who Eats Whom? Grade 5
Where a plant's food comes from, what happens when the wolves disappear, who cleans up, and how much life hides under a log. Four lessons on how energy and matter move through living things.
- Where does a plant get its food? 50–60 min, plus 10 min to weigh seedlings two weeks later
Students sink spinach leaf disks in baking soda water and watch them float back up in the light as they make oxygen, then start bean seedlings with no soil at all and weigh them two weeks later. They explain that plants build their food from air and water using light, not from the soil.
- What would happen if the wolves disappeared? 45–60 min
Students become species in a northern forest or a prairie and connect themselves with yarn into a living food web. When one species is removed, everyone who feels the yarn tug finds out how far the change spreads, and students explain why no species lives on its own.
- Who cleans up? 45 min to set up, 5 min check-ins twice a week, then 30 min after 2 weeks (bread) and 20 min after 4 to 6 weeks (leaves)
Students seal bread and fruit in taped zip bags to watch mould grow without ever opening them, and bury mesh bags of dry leaves in soil to weigh what's left weeks later. They explain how decomposers break down dead things and return matter to the soil for plants to use again.
- Can we count the life under a log? 50–60 min
Teams mark out a 1 m square in two different parts of the schoolyard, tally every kind of living thing they find, and compare the two sites. They explain which place supports more life and why, using the food webs and decomposers from earlier lessons.
Printable practice for B2.5
- Food Webs: Who Eats Whom? workbook included with the unit
3 practice pages, 3 readings, 2 English-support pages, 1 word wall, 1 unit review, 1 unit test, with answer keys.
- Our Living Planet workbook included with the unit
1 word wall, 1 English-support page, 1 practice page, 1 reading, 1 unit review, 1 unit test, with answer keys.
Need just this outcome? Build a custom pack from these pages, with its answer key, in about a minute. Custom packs come with All-access and school licences.
Compared with NGSS: 5-LS2-1.
More Ontario Grade 7 science outcomes we teach
Every Ontario Grade 7 science curriculum outcome we teach
Every unit matched to Ontario's curriculum · All places and curricula
Three full lessons, free
Make a free account and download any three Fieldbook lessons as printable PDFs. No card needed.