Choose the correct alternative and write its alphabet against the sub question number:
(1) ………………. beverage is obtained by fermentation of apple juice. (July ’19)
(A) Cider (B) Wine (C) Coffee (D) Cocoa
Ans. (A) Cider
(2) Salts which can be used as supplement of calcium and iron are obtained from …………………. (March ’20)
(A) carbonic acid (B) acetic acid (C) citric acid (D) gluconic acid
Ans. (D) gluconic acid
Name the following :
Write the molecular formula for : 4% Acetic acid (Vinegar) (Nov. ’20)
Ans. CH3COOH.
Complete the charts :
Ans.
(Nov. ’20)
Ans.
Textual Question:
*Microbial enzymes are used instead of chemical catalysts in chemical industry. (March ’19; Nov. ’20)
Solution covered in the notes provided on this website
Answer the following questions :
There is an oil layer on the water surface of river in your area. What will you do? (March ’19)
Ans. If there is an oil layer on the water surface, we shall use hydrocarbonoclastic bacteria like Pseudomonas to clean up the oil spill.
Explain the concept of bioinsecticides. (2 marks) (Sept. ’21)
Ans. (1) Bioinsecticides are chemicals that are obtained from bacterial, viral and fungal toxins. (2) Such toxins are incorporated into plants through biotechnological methods.
Textual Question:
* Which precautions are necessary for proper decomposition of domestic waste? (March ’20)
Solution covered in the notes
Textual Question:
* Why is it necessary to ban the use of plastic bags? (3 marks) (Sept. ’21)
Solution covered in the notes
Complete the following conceptual picture :
Textual Question: (March ’20)
Complete the paragraph using proper words : (March ’20)
(mechanical Rhizobium, aquatic, Toxic, CO2 Nitrogen, Pseudomonas, Amoeba, bacteria, hydrocarbons)
Spilling of petroleum oil occurs in ocean due to various reasons. This oil may prove fatal and toxic to ……………………… organisms. It is not easy to remove the oil layer from surface of water by ……………………. method. However, bacteria like ……………………………… spp. and Alcanovorax borkumensis have the ability to destroy the pyridines and other chemicals. Hence, these …………………….. are used to clear the oil spills. These are called hydrocarbonoclastic bacteria (HCB). HCB decompose the ……………………… and bring about the reaction of carbon with oxygen. …………………… and water is formed in this process.
Ans.
Spilling of petroleum oil occurs in ocean due to various reasons. This oil may prove fatal and toxic to aquatic organisms. It is not easy to remove the oil layer from surface of water by mechanical method. However, bacteria like Pseudomonas spp. and Alcanovorax borkumensis have the ability to destroy the pyridines and other chemicals. Hence, these bacteria are used to clear the oil spills. These are called hydrocarbonoclastic bacteria (HCB). HCB decompose the hydrocarbons and bring about the reaction of carbon with oxygen. CO2 and water is formed in this process.
Observe the Figure and answer the following questions : (March ’19)
(a) Identify the process shown in the figure.
Ans. The figure shows modern land fill site where microbial biodegradation process is carried out.
(b) Explain the process in short.
Ans. (1) In the land-filling sites the degradable wastes are transferred. Usually such sites are in urban areas. (2) The land-filling sites are away from the residential areas for the hygienic reasons. Here large pits are dug in open spaces. (3) These pits are lined with plastic sheets. Therefore, the leaching of toxic and harmful materials is avoided to reduce the chance of soil pollution due to leachates. (4) Compressed waste is put in the pit and is covered with layers of soil, saw dust, leafy waste. (5) Specific biochemical substances are added for speedy decomposition. (6) Bioreactors which are mixtures of bacteria are mixed at some places. (7) Soil microbes and other top layers decompose the waste. (8) Soil slurry is used to seal the pits completely. (9) After a certain period, best quality compost is formed. Such land filling sites can be reused after removal of compost.