It feeds upon grains hence called primary consumer and can also feed on insects hence called secondary consumer at the same time in the same ecosystem.

Correct Option: A

It feeds upon grains hence called primary consumer and can also feed on insects hence called secondary consumer at the same time in the same ecosystem.

Energy flow takes place only in one direction i.e., producers ? herbivores ? carnivores whereas, nutrients use carbon, nitrogen and potassium shows cyclic flow.

Correct Option: A

Energy flow takes place only in one direction i.e., producers ? herbivores ? carnivores whereas, nutrients use carbon, nitrogen and potassium shows cyclic flow.

The statement (i) and (ii) are correct.
The statement (iii) is incorrect because predators cannot lead to the extinction of prey species. Predator and prey evolve together.
The statement (iv) is incorrect because chemical such as nicotine and strychnine produced by the plants are not metabolic disorders but are metabolic wastes.

Correct Option: D

The statement (i) and (ii) are correct.
The statement (iii) is incorrect because predators cannot lead to the extinction of prey species. Predator and prey evolve together.
The statement (iv) is incorrect because chemical such as nicotine and strychnine produced by the plants are not metabolic disorders but are metabolic wastes.

The correct sequence of plants in a hydrosere is Volvox, Hydrilla, Pistia, Scirpus, Lanatana and Oak. A hydrosere is a plant succession which occurs in a fresh water lake. In time, an area of open fresh water such as a lake will naturally dry out, ultimately becoming woodland. During this change, a range of different landtypes such as swamp and marsh will succeed each other. The succession from open water to climax woodland is likely to take at least two hundred years.

Correct Option: A

The correct sequence of plants in a hydrosere is Volvox, Hydrilla, Pistia, Scirpus, Lanatana and Oak. A hydrosere is a plant succession which occurs in a fresh water lake. In time, an area of open fresh water such as a lake will naturally dry out, ultimately becoming woodland. During this change, a range of different landtypes such as swamp and marsh will succeed each other. The succession from open water to climax woodland is likely to take at least two hundred years.

A pond ecosystem is a delicate balance of fish, plants and other animals. Fish occupy more than one tropic level in pond ecosystem. Small fishes act as secondary consumer. They feed on primary consumer. Large fishes act as tertiary consumer. They feed on smaller fish.

Correct Option: A

A pond ecosystem is a delicate balance of fish, plants and other animals. Fish occupy more than one tropic level in pond ecosystem. Small fishes act as secondary consumer. They feed on primary consumer. Large fishes act as tertiary consumer. They feed on smaller fish.