Our environment Worksheet-12

Our environment Worksheet-12


  1. Consider the food chain. Grass → Deer → Lion. What will happen, if lions are removed from the above food chain?


  1. Give two main differences between a food web and food chain.


  1. The number of trophic levels in a food chain is limited. Why?


  1. "All the flesh of a carnivore is grass". Justify the statement.


  1. How much energy will be available to hawks in the food chain comprising hawk, snake, paddy and mice if 10,000 J of energy available to paddy from Sun?


  1. 'Man is only a consumer.' Justify the statement.


  1. Differentiate between carnivores and omnivores. Give one example each.


  1. The amount of energy that will be available to the plants from the sun is 20,000 J. Calculate the amount of energy available to the lion in the following food chain. Plant → Deer → Lion


  1. Calculate the amount of energy that will be available to big fish in the following food chain, if 10,000 J of energy is available to small algae from the Sun.

Small algae → Zooplankton → Fish → Big fish.


  1. Why do harmful chemicals concentrate as we go up in a food chain?


  1. What is ten per cent law? Explain giving examples.


  1. Draw a food chain with four trophic levels.


  1. Given below is a food chain : Grass → Grasshopper → Frog → Snake → Peacock.

What will happen to the members of different trophic level in the food chain, if all the frogs of that area are removed?


  1. With the knowledge of energy transfer in the food chain, man can place himself at an advantageous position in the food chain. Explain.


  1. A food chain consists of the following members. If the last member receives 30 J of energy, make a diagrammatic representation to show the flow of energy.Snake, Vulture, Plants and Rat.


  1. What are the two functions depicted by food chain?


  1. The shortening of food chains due to man's activities leads to imbalance in the functioning of an ecosystem. Explain this statement keeping the formation of Sahara desert as an example.


  1. The term producer for plants is misnomer. Explain why?


  1. What would happen if ozone layer in the atmosphere disappears?


  1. State any four environmental problems caused by man.