Natural Sciences Exam — Biomes, Adaptations and Biodiversity
Master ecology concepts: what an ecosystem is, how a food chain works (producers, consumers and decomposers), the main biomes of the planet (tropical rainforest, tundra, desert) and species relationships (mutualism, parasitism, commensalism).
An ecosystem is the network of relationships between living things and their environment: who eats whom, what each species needs to survive, and how a change in one link affects all the others. Understanding this network is the basis of ecology and why protecting biodiversity matters so much.
The exam covers food chains (producers, consumers and decomposers), the planet's main biomes —tropical rainforest, tundra, desert, taiga— with their characteristics, and relationships between species: mutualism, commensalism, parasitism and predation.
Build food chains and revise the planet's biomes with the exam below, with an explanation for every question.
Biology & Geology · Primary & Secondary
Producers (plants) → Primary consumers (herbivores) → Secondary consumers (carnivores) → Decomposers (fungi, bacteria). Energy is lost ≈90% at each level.
Tropical rainforest: most biodiversity. Tundra: permafrost, no trees, very cold. Desert: extreme dryness. Taiga: coniferous forest, long cold winters.
Mutualism (+/+): bees and flowers. Commensalism (+/0): clownfish in anemone. Parasitism (+/−): tick on dog. Predation (+/−): wolf hunts deer.
"A Year 7 student identified the rabbit in the chain grass→rabbit→fox→eagle as a "secondary consumer". After the exam, she understood it is a primary consumer (herbivore that eats producers)."
Tricks and techniques to master this topic faster:
Producers are always plants or algae. Herbivores are primary consumers. Carnivores eating herbivores are secondary consumers.
Decomposers (fungi, bacteria) close the matter cycle — without them nutrients would not return to the soil.
The tropical rainforest holds 50-80% of Earth's species despite covering only 6% of the land surface.
If you are studying Ecosystems — Food Chains and Biomes, these curriculum topics complement each other:
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