1. we do not clean ponds or lakes but an aquarium needs to be cleaned. why?
2. name two salt water system
3. write the fectors foe excessive solid waste genertion.
4. what are coliform bacteria?
5. one example of gRAZING FOOD CHAIN?

1. Ponds donot needed to be cleaned but aquarium needs to be cleaned. This is because aquarium do not contain soil and decomposing bacteria which helps in degrading complex organic substance into simple inorganic substance and act as a cleaner . But pond have this facility. Therefore, it do not needed to be cleaned whereas ponds do.

2 . ocean and lagoon

3 . factors for excessive solid waste generation are higher standard of living and rising population,factories , industries and mills

4. Coliform bacteria are bacteria which are found in small intestine of human . Their percentage in water is a measure to the level of pollution in water

5. grass -----> deer -------> tiger