Our environment Worksheet-7

Our environment Worksheet-7

 

  1. What are omnivores? Give one example.

 

  1. List two basic functions of food chain in the ecosystem.

 

  1. Which of the following belong to the same trophic level:

(a) Grass, hawk, rabbit, frog, deer.

(b) Grasshopper, spider, grass, hawk, lizard.

(c) Frog, grasshopper, grass, hawk, algae.

(d) Grasshopper, frog, snake, grass, lizard.

(e) Grass, grasshopper, frog, algae, snake.

(f) Frog, rabbit, hawk, grass, lion.

(g) Wheat plant, grasshopper, frog, deer, lion.

 

  1. Which two of the following belong to the same trophic level:

(a) Insects, algae, spider, snake, frog.

(b) Wheat plant, grasshopper, frog, deer, lion.

(c) Insects, grass, spider, snakes and algae?

 

  1. In the following food chain 5 J of energy is available to man. How much energy was available at producer level?

Plant    → Sleep   →   Man

500 J         50 J           5 J

 

  1. Which organisms belong to third and fourth trophic levels in the food chain comprising of the following:

Rats, Plants, Hawks, Snakes

 

  1. Which one of the following is not a part of the biotic environment :

(a) Water, Algae, Fish, Bacteria.                

(b) Insects, Air, Plants, Birds.

(c) Man, Air, Trees, Insects

 

  1. Population of which organisms is generally minimum in an ecosystem?

 

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

 

  1. In comparing the two ecosystems 'A' and 'B', it is observed that 'A' has only first and second order consumers, while 'B' has third, fourth and fifth order consumers. Which of the two would be more stable?

 

Answer:

  1. Animals which depend on plants as well as other animals are omnivores, e.g., man.

 

  1. (i) Food chain transforms solar energy into chemical energy and transfers chemical energy   among the members of the chain.

(ii) It maintains ecological balance.

 

  1. (a) Rabbit and deer (II trophic level)

(b) Spider and lizard (III trophic level)

(c) Grass and algae (I trophic level)

(d) Frog and lizard (III trophic level)

(e) Grass and algae (I trophic level)

(f) Frog and lion (III trophic level)

(g) Grasshopper and deer (II trophic level)

 

  1. (a) Spider and frog. (III trophic level)

(b) Grasshopper and deer (II trophic level)

(c) Algae and grass (I trophic level)

 

  1. 500 J of energy is at the plant level which is transferred to sheep.

 

  1. Snakes belong to third trophic level and Hawks belong to fourth trophic level.

 

  1. (a) Water,   (b) Air,   (c) Air.

 

  1. Predators which lie at the top of food webs are generally minimum in an ecosystem.

 

  1. Snakes.

 

  1. A will be more stable because it has lesser number of trophic levels.