A series of organisms that are linked to each other through a process of eating and being eaten form a

1. food net
2. food chain
3. food web
4. none of these

The plants or the producers which fix the solar energy constitute the

1. second trophic level
2. third trophic level
3. fourth trophic level
4. first trophic level

Animals that are active at night are called

1. diurnal animals
2. nocturnal animal
3. aquatic animals
4. terrestrial animals

Which of these is not a terrestrial ecosystem

1. pond
2. grassland
3. desert
4. mountain