Human impacts on biodiversity and ecosystem services are the focus of this Grade 9 Science worksheet, connecting environmental changes caused by people to the health of ecosystems and the benefits they provide. Students examine how land conversion, habitat fragmentation, pollution, resource extraction, invasive species, and greenhouse gas emissions can affect species survival, ecosystem relationships, and services people rely on.

Trace the effects of human activity

The reading passage introduces biodiversity as the variety of living things in an area and explains how environmental pressures can change ecosystems. Students explore how roads, farms, and buildings replace natural habitats, while fragmentation divides remaining habitats into smaller patches. These changes can isolate wildlife populations and make it harder for organisms to find mates, food, or shelter.

Pollution provides another way to investigate cause and effect. The passage connects fertilizer runoff with excessive algae growth and reduced oxygen in aquatic environments, and explains how chemical contaminants can affect organisms through food webs. Students also consider how greenhouse gas emissions contribute to climate change and influence habitats and species distributions.

Connect biodiversity with ecosystem services

This environmental science resource moves beyond identifying threats to examine why biodiversity matters. Students connect pollinators with plant reproduction, wetlands with water filtration, and soil organisms with soil formation. They consider how declining species diversity may make these services less reliable, and how vegetation loss, soil erosion, and damaged habitats can influence ecosystem functioning. The focus is on explaining relationships between human activities, ecological changes, and benefits that support people.

What students practise

• Multiple-choice questions that assess biodiversity, habitat connectivity, fertilizer runoff, land conversion, pollination, contaminants in food webs, vegetation loss, conservation actions, and climate-related ecosystem effects.
• True-or-false statements that address habitat fragmentation, wetland water filtration, invasive species, pollution pathways, and the reliability of ecosystem services.
• Short-answer responses requiring students to explain population isolation, describe changes in aquatic ecosystems following fertilizer runoff, and connect species decline with reduced ecosystem services.
• A labeled diagram, categorization activity, and short-note task that extend practice beyond selected-response questions.

Included for classroom use

• Printable student worksheet covering the stated biodiversity and ecosystem topics.
• Separate PDF answer key for checking student responses.
• Student Notes lines at the bottom of the worksheet for recording key ideas.
• Teacher Guide inside the Answer Key PDF, with Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes.

Ways to use this resource

Use the worksheet during a Grade 9 ecology and environmental interactions unit, as guided reading followed by independent practice, or as a review of human effects on ecosystems. The written explanations can help teachers identify whether students can connect a cause, such as habitat fragmentation or pollution, with a specific ecological consequence. The answer key and embedded teacher guidance provide support for checking work and preparing follow-up discussion.

The resource is identified with the TEKS framework, but the supplied details do not specify an individual TEKS code or demonstrate alignment to a particular standard. It is best suited to lessons addressing biodiversity, ecosystem services, human environmental impacts, and ecological cause-and-effect relationships.