Class 12th Biology 2017 Set1 Delhi Board Paper Solution
Public all over India is very much concerned about the deteriorating air quality in large parts of North India. Alarmed by this situation the Resident’s Welfare Association of your locality organised an awareness programme entitled ‘Bury not burn’. They invited you, being a biology student to participate.
(a) How would you justify your arguments that promote burying and discourage burning? (Give two reasons)
(b) With the help of flow charts, one for each practice, depict the chain of events that follow.
(a) Following arguments can be put forward to promote burying and discourage burning:
(i) When we burn wastes, pollutants such as carbon dioxide, NO2 , SO2 , etc. are released in the atmosphere. These pollutants damage the environment. Due to burning, smoke is released into atmosphere which causes problems like asthma, emphysema, etc.
(ii) Burying the waste does not have any harmful effect in fact when we bury organic wastes, the soil becomes enriched with nutrients.
(b) The solid wastes are of two types:
Biodegradable wastes These can be degraded by the microbes, e.g. organic waster paper, etc.
Non-biodegradable wastes These cannot be degraded by the microbes and can remain as such for long periods, e.g. plastic. Flow charts depicting effects of burying and burning are:
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