List the events that reduce the Biological Oxygen Demand (BOD) of a primary effluent during sewage treatment.
After the primary treatment, the primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and air is pumped into it.This leads to the vigorous growth of useful aerobic microbes (Flocs of bacteria and fungi). The microbes consume a major portion of the organic matter of the effluent and thus reduce the BOD significantly.
Mention the kind of biodiversity of more than a thousand varieties of mangoes in India represent. How is it possible?
Name the causative organism of the disease amoebiasis. List three symptoms of the disease.
Suggest the breeding method most suitable for animals that are below average in milk productivity.
