Q.

Which of these is NOT a correct sequence of a food chain

1 Phytoplanktons  Zooplanktons  Fish  
2 Seed grains  Rodents  Eagle  
3 Grass  Insects  Frog  Snake  
4 Seaweed  Zooplanktons  Phytoplanktons  

Ans.

(4)

Phytoplanktons are the primary producers. They should occupy the first trophic level in the aquatic food chain.