K325 / 2027

Chapter 11 / 9 short lessons

Organisms and their environment

Follow energy and carbon through ecosystems, explain pollution and assess ways to protect biodiversity.

G3 Pure Biology / K325 / 2027 syllabus

What do you think?

In a food chain, does grass point towards a grasshopper, or does the grasshopper point towards the grass?

Lessons

0 of 9 marked as read
01

Reading food chains and food webs

Identify producers, consumers and decomposers and interpret feeding relationships.

About 5 min
About 5 min
02

Why less energy reaches the next level

Explain one-way energy flow and calculate the efficiency of transfer between trophic levels.

About 5 min
About 5 min
03

Pyramids of numbers and biomass

Construct and interpret pyramids while distinguishing counts from mass.

About 5 min
About 5 min
04

Following carbon through an ecosystem

Trace carbon transfers and explain the roles of forests and oceans as carbon sinks.

About 5 min
About 5 min
05

Carbon dioxide and global warming

Explain increased atmospheric carbon dioxide and connect mitigation actions to their mechanisms.

About 6 min
About 6 min
06

Why sewage can remove oxygen from water

Explain the effects of sewage using decomposition, respiration and dissolved oxygen.

About 5 min
About 5 min
07

Plastic waste in marine ecosystems

Explain harm from marine plastic waste and compare prevention and removal actions.

About 4 min
About 4 min
08

Biomagnification along a food chain

Explain biomagnification using persistence, uptake and repeated feeding.

About 5 min
About 5 min
09

Conservation and sustainable use

Explain how species conservation and sustainable resource use maintain biodiversity and ecosystem relationships.

About 5 min
About 5 min
What you will be able to do
  • Interpret feeding relationships and energy transfers.
  • Distinguish carbon cycling from energy flow.
  • Explain environmental impacts and evaluate conservation actions.

Ready to try it without your notes?

Start with a quick check or explain a biological result in your own words.

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