Marine eco-system includes the oceans, estuaries and 

Which of the following food chain starts with a plant.

Which is the basic source of energy on which all life depends

Who converts some of the consumed carbohydrates into carbondioxide for release into the air through respiration.

A network of inter connecting food chains is known as

Which of the following constituent of the atmosphere comprising about seventy-nine percent of the atmospheric gases.

 How many major biomes are there in the world.

Which of the following element  is very significant in the environment.

The study of the earth as a household, of plants, human beings, animals and micro-organisms is called

Which of the following is the main by-product of photosynthesis.