Ch-15 Our Environment (Question) Page264

Question 1:	What is ozone and how does it affect any ecosystem?
Answer :	Ozone is a colourless gas that acts as a screen for ultraviolet radiation. It is continuously formed at the higher levels of the atmosphere due to the action of UV rays on molecular oxygen. The high energy UV radiations break down O2 molecules into nascent oxygen. Then, this free oxygen atom combines with an oxygen molecule to form ozone. In recent years, the amount of ozone in the atmosphere is getting depleted. This ozone depletion causes a greater amount of ultra violet radiation to enter earth’s atmosphere. This has an indirect effect on theecosystem.(Ecosystem includes both the biological community and the non-living components of an area). It results in the death of many phytoplanktons, thereby affecting the process of photosynthesis. Plants utilise atmospheric CO2 to make their food. In the absence of plants, the levels of CO2 in the atmosphere will increase, which would in turn lead to an increase in global warming. The depletion in the ozone layer also increases the frequency of infectious diseases as it suppresses the immune systems of both human beings and animals. The frequency of skin cancer also increases in human beings because of the direct exposure to ultraviolet radiations.
Question 2:	How can you help in reducing the problem of waste disposal? Give any two methods.
Answer :	The problem of waste disposal can be solved by proper waste management including the collection, transport, processing, and disposal of the waste materials. The problem of waste management can be solved by the following given measures: Use separate bins (blue and green) for disposing non-biodegradable and biodegradable wastes. Different garbage bins for disposing biodegradable  waste and non-biodegradable waste Reduce the usage of non-biodegradable products such as plastics.