Question

Read the following statements (a-e) and answer the question which follows them
(a) Dragonflies are used for controlling aphids
(ii) Rumen is rich in methanogens
(iii) increase in organic pollution increases BOD
(d) man made technology for treatment of sewage is better than microbial treatment
(e)Lipases are commercially used in detergents
How many of the above statements are correct?

• A. one
• B. two
• C. three
• D. four

Answer 1

Answer: (D)

four

Delicate dragonflies can rid the yards of aphids (small sap sucking insects) and mosquitoes and other insect pests. Methane is produced in the rumen and hindgut of animals by a group of Archaea known collectively as methanogens, which belong to the phylum Euryarcheota. Among livestock, methane production is greatest in ruminants, as methanogens are able to produce methane freely through the normal process of feed digestion. A high BOD (biological oxygen demand) means that there is plenty of organic matter present. Microbial treatment is an integral part of the sewage disposal and hence cannot be said that man-made treatment of sewage is better. The cleaning power of lipase (or other enzyme containing) detergents increases markedly. The enzymes such as proteases, amylases, cellulases, and lipases are added to the detergents to improve their efficiency.

So, the correct answer is 'Four'.