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Science · 2025 · 2 marks
CBSE 2025 · Region 6 · Set 1 · Q26
We do not clean natural ponds or lakes whereas an aquarium or a swimming pool needs to be cleaned regularly. Why?
We do not clean natural ponds or lakes whereas an aquarium or a swimming pool needs to be cleaned regularly. Why ?
Marking-scheme solution
Ponds or lakes have natural cleansing agents like microbes which clean the ponds or lakes. whereas an aquarium or a swimming pool is an artificial/man-made ecosystem and do not have decomposers. If we do not clean the aquarium regularly the waste material will go on increasing which is harmful for fishes and aquatic plants.
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