Lessons 3–4 · 2 lessons · K. T. Suyarov, Z. B. Sangirova, M. T. Umaraliyeva, S. G‘. Xasanova, M. K. Yuldasheva, D. T. Hasanova. Natural Science, Grade 6 (new edition). Republican Education Centre, 2022
4
Project: Building an ecosystem model
Textbook, pp. 13–14
GoalExplain the living and non-living parts of an ecosystem and the cycle of matter between them, and build an ecosystem model.
New words
ecosystem (living and non-living parts that act on each other) · ekosistemamodel (a simplified copy used to study something) · modelphotosynthesis (plants make organic matter using light) · fotosintezmicroorganisms (tiny living things, e.g. bacteria) · mikroorganizmlar
Explanation
An ecosystem is a place where living and non-living parts exist together and act on each other. The living part includes plants, animals, fungi and bacteria; the non-living part includes stone, soil, water and gases of the air. Plants take water and minerals from the soil and make organic matter in photosynthesis. Herbivores eat plants and predators eat herbivores. Microorganisms in the soil break down the remains of organisms and turn them back into minerals, which plants take up again – so matter circulates in the ecosystem. A model is a simplified copy of a real object that lets us study it on a small scale.
Worked examples
In a lake: plants, fish, bacteria – living part; water, sand, oxygen – non-living part. If a fish dies, bacteria break it down and algae use the minerals produced.
A jar model: from the bottom up, sand, gravel, a layer of soil, and a slow-growing plant on top. The jar is a small ecosystem, but it differs from a natural one by its small size and the absence of animals.
Class activity
Project: build an ecosystem model in a clear plastic container: sand and small gravel at the bottom, a layer of soil on top, 2–3 slow-growing plants in it (for example spider plant), spray with water, and add stones and dry twigs for decoration. Safety: use a plastic container instead of glass, wear gloves or wash hands well after handling soil, and never taste fertiliser. Keep the model in a bright place (not in direct sun) and observe it for two weeks.
Practice
1
Give three examples each of the living and non-living parts of an ecosystem.