Question

We do not clean ponds or lakes, but an aquarium needs to be cleaned because
A. An aquarium is an artificial and incomplete ecosystem.
B. Pond/lake are natural, self-sustaining and complete ecosystems.
C. Both A and B.
D. None of the above.

Answer 1

Hint: An aquarium can be a container like glass tanks or artificial ponds in which aquatic flora and fauna are kept and exhibited. Ponds and lakes are naturally existing water bodies.

Complete Answer:
Ponds and lakes being natural ecosystems have natural decomposers and cleaners embedded as an integral part of the ecosystem, hence we do not have to clean them.

Aquariums are artificially built ecosystems which generally do not contain every aspect of a natural ecosystem. These artificial systems do not contain any form of natural decomposers and cleaners in the ecosystem as a result, food and waste generated by the organisms living in the aquarium accumulate and contaminate the water in the tank making it toxic. Hence they have to be cleaned manually.

Now, let us look at each option one by one.
- An aquarium is an artificial and incomplete ecosystem. The claim made in this statement holds true for the statement given in the question. Therefore, it is a part of the answer for the above question.
- Ponds are natural, self-sustaining and complete ecosystems. The claim made in this statement holds true for the statement given in the question. Therefore, it is a part of the answer for the above question.
- Since the claims made in the options (A) and (B) hold true for the statement given in the question; therefore, this is the correct option.
- Since the claims made in the options (A) and (B) hold true for the statement given in the question; therefore, this option is incorrect.

Thus the correct answer for the given question is (C) Both A and B.

Note: In an aquarium, along with the absence of natural cleansers and decomposers, other abiotic factors such as sunlight, etc, are also absent. So, the ecosystem in the aquarium has to depend on the technology made by man for survival.