Our environment Worksheet-8

Our environment Worksheet-8


  1. With the help of arrows depict the aquatic (in a pond) food chain.


  1. What is a 'decomposer'?


  1. Write the food chain of a non-vegetarian.


  1. Name the organism belonging to the 4th trophic level in the food chain comprising the following: Snakes, Insects, Frogs, Plants, Hawks.


  1. Which one of the following is not a terrestrial ecosystem : Forest, Grassland, Aquarium, Desert


  1. Arrange the following in a food chain :

(a) Frogs, Insects, Birds, Grass.

(b) Fish, Algae, Small Animal, Big Fish.


  1. State one reason to justify the position of man at the apex of most food chains.


  1. Name the process in which harmful chemicals enter food chain and get concentrated more and more at its each successive trophic level of organism.


  1. What are those animals called who depend upon only plants for their food?


  1. If a harmful chemical enters a food chain comprising snakes, hawks, mice and plants, which of these organisms is likely to have maximum concentration of the harmful chemicals in its body?


  1. What are planktons?


  1. Name the organisms belonging to the second and fourth trophic levels in the food chain comprising the following : Frogs, Plants, Snakes, Hawks, Insects.


  1. Construct a food chain comprising the following: Snakes, Hawks, Rats, Plants.


  1. In a food chain comprising of lion, grass and deer, which one will transfer maximum energy to the next trophic level?


  1. Identify the organism belonging to the third trophic level, by constructing a food chain, comprising the following organisms : Snake, Mice, Hawk, Plants.


  1. Define an ecosystem.


  1. Define trophic level.


  1. What are producers? Give suitable examples.


  1. What is the functional unit of environment comprising of the living and non-living components called?


  1. What are the various steps of a food chain called?



  1. Phytoplanktons → Zooplanktons → Small fishes → Large fishes.


  1. Group of micro-organisms that breaks the complex dead organic matter into simpler substances by a natural process is called decomposers.


  1. Grass → Goat → Man.


  1. Snakes.


  1. Aquarium.


  1. (a) Grass → Insects → Frogs → Birds.

(b) Algae → Small animals → Small fishes → Big fishes.


  1. Man is omnivorous and due to the power that he yields over other animals he is very rarely eaten by other animals. Also, he disposes the dead ones in such a way that they cannot be eaten by scavengers.


  1. Biological concentration or biomagnification.


  1. Herbivores (I order consumers).


  1. Hawks.


  1. Planktons are very minute microscopic organisms freely floating on the surface of water in a pond, lake, river or ocean.


  1. Insects belong to second trophic level and snakes belong to fourth trophic level.


  1. Plant → Rats → Snakes → Hawks.


  1. Grasses will transfer maximum energy to deer.


  1. Snake: Plants → Mice → Snake → Hawk.


  1. A functional and self-sustaining unit comprising of living and non-living components in which there is a constant interaction between the two is an eco-system.


  1. The various steps of a food chain through which energy is transferred to the successive levels in the form of food is called trophic level.


  1. Producers are green plants, that can transform solar energy into chemical energy by the process of photosynthesis, e.g., Grass, Algae.


  1. Ecosystem.


  1. Trophiclevels.