Food Webs and Matter Cycles is a Grade 7 Science worksheet focused on how energy flows through ecosystems, how carbon and water cycle through the environment, and how pollutants can affect organisms at different feeding levels. Designed for Alberta's Science 7: Interactions and Ecosystems topic, this resource connects food web relationships with matter cycling and population changes.

Students explore the relationships among producers, consumers, and decomposers while tracing how materials move between living things and the nonliving environment. Instead of studying each concept in isolation, they practise explaining how changes in one part of an ecosystem can influence other organisms and environmental processes.

From feeding relationships to ecosystem change

The reading passage introduces the roles of plants and algae as producers, herbivores, carnivores, omnivores, and decomposers such as fungi and bacteria. Students examine energy transfer through feeding relationships and how decomposers return nutrients to the environment.

The lesson also covers the carbon cycle, including photosynthesis, respiration, decomposition, and combustion. Water-cycle concepts include evaporation, condensation, precipitation, surface flow, infiltration into soil, and plant absorption. Students encounter biomagnification and consider why persistent pollutants can become more concentrated at higher feeding levels, particularly in top predators.

Questions about predator and prey relationships encourage students to predict how population changes may affect plants, consumers, and the wider food web. The resource also highlights scientific observations, measurements, and models as ways to investigate and communicate ecosystem evidence.

What students practise

• Multiple-choice questions that assess food web relationships, energy transfer, decomposers, matter cycles, pollutants, and ecosystem models.
• True-or-false statements that reinforce accurate explanations of nutrient recycling, water movement, biomagnification, and population interactions.
• Short-answer responses explaining carbon movement, pathways of water after precipitation, and possible consequences of predator population changes.
• A labeled diagram activity, a categorization task, and a short-note activity.

Included with your resource

• The student worksheet with a reading passage and varied practice activities.
• Student Notes lines at the bottom of the worksheet for recording key ideas.
• A separate PDF answer key for checking student responses.
• A Teacher Guide included in the answer key PDF, featuring Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes.

Ways to use this ecosystem science worksheet

Use this Grade 7 food webs and matter cycles resource during an Interactions and Ecosystems unit, after teaching food chains and nutrient cycles, or as independent practice following a lesson discussion. The reading passage provides context before students answer questions, while the explanatory prompts give them opportunities to connect scientific vocabulary with cause-and-effect relationships.

The predator-change scenario can support classroom discussion about interconnected populations, while the water and carbon questions reinforce the idea that matter moves through multiple pathways. The separate answer key and teacher guidance also support lesson preparation, independent review, and checking student understanding.

This Alberta Grade 7 science practice resource brings together energy flow, carbon and water cycles, biomagnification, and ecosystem interactions in one coherent learning sequence, helping students develop a more connected explanation of how ecosystems function.