In this Grade 7 Life Science lesson from Chapter 14, students learn how matter continuously cycles through ecosystems, focusing on the water cycle, carbon cycle, and nitrogen cycle. Students explore key processes such as evaporation, transpiration, condensation, photosynthesis, and respiration, and how these processes move water and carbon between living organisms and their nonliving environment. The lesson builds foundational understanding of how matter changes form but is never lost within an ecosystem.
Section 1
Water Transforms Through Multiple States in Ecosystems
Water moves continuously between gas, liquid, and solid forms through precipitation, evaporation, transpiration, and respiration. This endless cycle distributes water throughout Earth's surface, atmosphere, and living organisms.
Section 2
Plants Convert Carbon Dioxide Into Living Matter
During photosynthesis, plants absorb carbon dioxide to produce sugars, forming the foundation of food chains. When organisms break down these compounds during respiration, carbon returns to the atmosphere as CO₂.
Section 3
Bacteria Transform Atmospheric Nitrogen Into Usable Forms
Nitrogen-fixing bacteria convert atmospheric nitrogen into compounds plants can absorb through roots. When organisms die, decomposers release nitrogen back into soil or water, allowing it to cycle through ecosystems again.
Section 4
Matter Cycles Rather Than Disappears
Elements like carbon, nitrogen, and water continuously move between living organisms and their environment. Though matter changes form through various processes, it remains within the ecosystem, creating endless cycles.
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Section 1
Water Transforms Through Multiple States in Ecosystems
Water moves continuously between gas, liquid, and solid forms through precipitation, evaporation, transpiration, and respiration. This endless cycle distributes water throughout Earth's surface, atmosphere, and living organisms.
Section 2
Plants Convert Carbon Dioxide Into Living Matter
During photosynthesis, plants absorb carbon dioxide to produce sugars, forming the foundation of food chains. When organisms break down these compounds during respiration, carbon returns to the atmosphere as CO₂.
Section 3
Bacteria Transform Atmospheric Nitrogen Into Usable Forms
Nitrogen-fixing bacteria convert atmospheric nitrogen into compounds plants can absorb through roots. When organisms die, decomposers release nitrogen back into soil or water, allowing it to cycle through ecosystems again.
Section 4
Matter Cycles Rather Than Disappears
Elements like carbon, nitrogen, and water continuously move between living organisms and their environment. Though matter changes form through various processes, it remains within the ecosystem, creating endless cycles.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter