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प्रश्न
Why does the increased level of nutrients in the water affect the survival of aquatic organisms?
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उत्तर
An increase in the level of nutrients in a water body leads to an excessive increase in the population of algae in the water body. When these algae die, they serve as food for decomposers. A lot of oxygen is utilised in this process, consequently leading to a decrease in the level of oxygen dissolved in the water body. This in turn causes fishes and other aquatic organisms to die.
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संबंधित प्रश्न
The activities of man had adverse effects on all forms of living organisms in the biosphere. Unlimited exploitation of nature by man disturbed the delicate ecological balance between the living and non-living components of the biosphere. The unfavourable conditions created by man himself threatened the survival not only of himself but also of the entire living organisms on the mother earth. One of your classmates is an active member of 'Eco club' of your school which is creating environmental awareness amongst the school students, spreading the same in the society and also working hard for preventing environmental degradation of the surroundings
List two values exhibited by your classmate who is an active member of Eco-club of your school.
Give one example each from your daily life where the domestic waste can be effectively reused and recycled.
What measures would you take to conserve electricity in your house?
The use of one of the following is eco-friendly. This one is :
(a) cars for transportation
(b) polybags for shopping
(c) windmills for generating power
(d) dyes for colouring clothes
In a village, farmers started cultivating crops all around a lake which was always filled with water. They added lot of materials W to the soil in their fields to increase the yield of crops. Soon they found that the whole surface of water in the lake was covered with a green layer made up of tiny organisms X. After some time, the fish present in the lake started dying in large numbers because they could not get sufficient Y due to a process Z which had occurred in lake water and drained out all the Y present in the water of lake.
(a) What do you think materials W are?
(b) Name (i) X, and (ii) Y.
(c) What is the process Z known as?
(d) What happens during the process Z which uses up all the Y present in lake water?
(e) What does this example tell us about the use of materials like W?
Suggest some approaches towards the conservation of forests.
List five things you have done over the last one week to −
increase the pressure on our natural resources
Answer the following question.
Why should there be an equitable distribution of resources? List three forces that would be working against an equitable distribution of our resources.
The main cause for abundant coliform bacteria in the river Ganga is
