Main idea

Living conditions and plant and animal communities are connected through food chains into a biological cycle. Dead organic matter represents food for plants, which is food for animals.

Goal

To explain to the students how various living organisms are connected through food chains into a biological cycle and why water cleans through the biological cycle.

Concepts

food chains -> biological cycle -> water purification processes

Introduction: What is a food chain?

Together with students, try to figure out what food chains are.

Activities in this lesson

Biological Cycle
3.3.1
Subject: Biology, Chemistry, Language
Age group: 10 - 12, 13 and up
Type of activity: Debate, Project
Number of participants: Individual, Paired, Team
Our river
3.3.2
Subject: Biology
Age group: 10 - 12, 13 and up
Type of activity: Debate, Project
Number of participants: Individual, Paired, Team

Discussion: How organisms purify water

Discuss with students how water organisms purify water from organic pollution. (Organic pollution from homes and farms represents food for some macroinvertebrates and bacteria that use it as food and decompose it in inorganic matter, which is used by plants and algae for their growth. Water purifies itself through including organic pollution in food chains in the biological cycle.)