Ecological interactions and trophic relationships shape how species coexist, transfer energy, and maintain biodiversity. This Grade 12 Science worksheet for Biology 30 explores competition, predation, parasitism, mutualism, and commensalism alongside food webs, trophic levels, and ecosystem resilience. Students apply these concepts to Alberta ecosystems, examining the relationship between wolves, elk, and vegetation and the mutualistic association between aspen trees and mycorrhizal fungi.

By connecting species interactions to real ecological examples, this resource encourages students to explain more than definitions. They investigate how changes in one population can affect other organisms, why biomass generally decreases at higher trophic levels, and how relationships between species influence community composition over time.

From species relationships to ecosystem-wide effects

The reading passage introduces the major types of ecological interactions and explains how producers, consumers, and decomposers contribute to food webs. Students examine why only part of the energy available at one trophic level becomes biomass for the next, with much of the energy supporting metabolism or being released as heat.

Alberta examples bring these ideas into context. The wolf–elk–vegetation trophic cascade illustrates how changes in predation can influence grazing and plant growth, while the aspen–mycorrhizal relationship demonstrates mutualism through the exchange of sugars, water access, and minerals. Students also consider how ecological relationships affect biodiversity, species abundance, and ecosystem resilience.

What students practise

• Reading comprehension: Identify key ecological relationships, energy-transfer principles, and examples from Alberta ecosystems.
• Multiple-choice questions: Apply knowledge of resource competition, parasitism, mutualism, commensalism, producers, decomposers, and trophic cascades.
• True-or-false statements: Evaluate claims about energy transfer, host–parasite relationships, mycorrhizal associations, and interactions across food-web levels.
• Short-answer questions: Explain how competition affects species abundance, trace possible effects of wolf predation on elk and vegetation, and justify why aspen–fungus associations represent mutualism.
• Labeled diagram and categorisation activities: Reinforce ecological relationships through visual interpretation and classification.
• Short-note activity: Record important concepts for future review.

Included with your worksheet

• Printable Grade 12 Science worksheet focused on community interactions and trophic relationships.
• Separate PDF answer key for checking student responses.
• Student Notes lines at the bottom of the worksheet.
• Teacher Guide within the answer key PDF, featuring Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes.

Classroom use and teaching value

Use this ecology worksheet during Biology 30 lessons on ecological communities, as independent practice after direct instruction, or as a review resource before an assessment. The passage establishes the scientific context, while the questions give students opportunities to distinguish similar interaction types and explain cause-and-effect relationships across an ecosystem.

The Alberta-focused examples make abstract ecological principles easier to discuss in a regional context. Students can connect predator–prey relationships and plant–fungus mutualism to broader questions about biodiversity, community structure, and ecosystem function. The separate answer key and included teacher guidance support efficient marking and provide prompts for classroom discussion.

This resource is suited to teachers seeking focused Grade 12 ecology practice that combines ecological vocabulary, energy transfer, species interactions, and applied ecosystem reasoning in one printable worksheet package.