Starfish are echinoderms belonging to the class Asteroidea. All are marine with organ-system level of organization.

Correct Option: A

Starfish are echinoderms belonging to the class Asteroidea. All are marine with organ-system level of organization.

Escherichia and Agrobacterium

Correct Option: A

Escherichia and Agrobacterium

Chamydomonas nivalis

Correct Option: A

Chamydomonas nivalis

Western Himalayas

Correct Option: B

Western Himalayas

Eutrophication is the enrichment of bodies of fresh water by inorganic plant nutrients (e.g., nitrate, phosphate). These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms, such as fish.

Correct Option: B

Eutrophication is the enrichment of bodies of fresh water by inorganic plant nutrients (e.g., nitrate, phosphate). These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms, such as fish.