Anil Ahlawat Solutions for Chapter: Pollution of Air and Water, Exercise 1: EXERCISES
Anil Ahlawat Science Solutions for Exercise - Anil Ahlawat Solutions for Chapter: Pollution of Air and Water, Exercise 1: EXERCISES
Attempt the practice questions on Chapter 17: Pollution of Air and Water, Exercise 1: EXERCISES with hints and solutions to strengthen your understanding. NSO Science Olympiad Workbook Grade 8 solutions are prepared by Experienced Embibe Experts.
Questions from Anil Ahlawat Solutions for Chapter: Pollution of Air and Water, Exercise 1: EXERCISES with Hints & Solutions
The greenhouse effect refers to the _____.
Refer to the given food web.
If a non-biodegradable insecticide known as DDT was sprayed onto the pine tree, in which of the following organisms will most of the DDT eventually accumulate?
Match column I with column II and select the correct option from the codes given below.
| Column I | Column II | ||
| (a) | Carbon dioxide in the air | (i) | Damage ozone layer |
| (b) | Sulphur dioxide in the air | (ii) | Produces acid rain |
| (c) | Chlorofluorocarbons | (iii) | Prevents photosynthesis |
| (d) | Dust in air | (iv) | Lead to global warming |
An oil spill covered a large area of water in an ocean. The marine life in that area was badly affected. A lot of marine animals were found dead and floating on the surface of the water. This is because
(i) They drank the water that was contaminated by the oil
(ii) The fish swallowed the oil and were poisoned
(iii) They breathed in the oil fumes near the water surface and were suffocated
Following are the steps of purification of water.
(i) Water collected from the river is made free of large pieces of dirt and pumped into reservoirs.
(ii) Water is passed through filter beds.
(iii) Water is stirred in a flocculation tank.
(iv) Water is allowed to stand in large tanks.
(v) Water is chlorinated.
(vi) Filtered water is stored.
(vii) Water is supplied to homes and factories by huge water mains.
Select the option which arrange the steps in correct sequence.
The events which occur in the water body after it has been polluted by fertilisers are given as follows:
(i) Submerged algae perish
(ii) Water plants undergo sudden proliferation
(iii) Consumers such as fish die
(iv) Oxygen levels fall
(v) Bacteria act on the increased number of dead organisms.
Arrange them in a correct sequence.
As proved by many studies greenhouse effect is rapidly increasing because of the increase in the concentration of carbon dioxide. In the given graph the increase in carbon dioxide concentration is shown. What could be X corresponding to it?
(i) Rate of photosynthesis in plants
(ii) pH of the oceans
(iii) Water level of the ocean
(iv) Average global temperature of Earth
Which of the following are possible advantages of using bacteria in sewage treatment?
(i) Bacteria multiply quickly, thus producing a cheap and abundant source of enzymes.
(ii) Only one type of bacteria is required to provide the various enzymes necessary for different kinds of wastes.
(iii) Bacteria can break down waste under anaerobic or aerobic condition.
