Question 1
Question: Define environment.
Answer: Environment is defined as the surroundings in which the organism lives.
Question 2
Question: How is the environment classified into three types?
Answer: The environment may be classified into three types based on the nature of its components. The physical environment that includes the physical features of the environment, the chemical environment that includes the chemical substances that make up the environment and the biological environment that includes the living organisms.
Question 3
Question: What are the two components of the environment?
Answer: The two components of the environment are the biotic (plants, animals and microbes) and the abiotic (non-living component).
Question 4
Question: Define conservation of environment.
Answer: Maintaining and judiciously using the environment is called conservation.
Question 5
Question: Name any four environmental problems faced by today's world.
Answer: Four environmental problems being faced by today's world are:
1) Population explosion
2) Pollution
3) Global warming
4) Soil erosion
Question 6
Question: Why is ozone layer important?
Answer: Ozone layer is important for us as it protects us from the harmful ultraviolet rays.
Question 7
Question: How does municipal waste contribute to air pollution?
Answer: Municipal waste consists of organic matter. The decomposition of this under anaerobic conditions produces methane. Methane produces carbon monoxide on oxidation. The municipal wastes also contribute to air pollution by producing foul smelling gases on decomposition.
Question 8
Question: What is greenhouse effect?
Answer: Earth is surrounded by an envelope of gases. Most of the solar radiation that reaches the earth is reflected back. However, some of the heat is absorbed by the gases like carbon dioxide that form an insulating layer around the earth. This heating of earth by the insulating effect of the gases is called greenhouse effect.
Question 9
Question: What is ozone? How is it beneficial to us?
Answer: Ozone (O3) is a gas present in the stratosphere of the atmosphere. Ozone is known to absorb the ultraviolet (UV) rays present in the sun's radiation. The UV rays are believed to cause skin cancer and mutations. Thus, the ozone protects us from the harmful effects of the UV rays.
Question 10
Question: What is oxygen depletion?
Answer: The sewage contains the organic matter that encourages the growth of microorganisms. These organisms consume the oxygen present in water. This reduces the oxygen content of the water. This is called oxygen depletion. The aquatic organisms like the fish cannot then survive in such waters.
