Q.1. Which of the following is put into Anaerobic sludge digester for further sewage treatment ? (2020)
(a) Effluents of primary treatment
(b) Activated sludge
(c) Primary sludge
(d) Floating debris
Major portion of activated sludge is pumped into large tanks called anaerobic sludge digesters. So, here other kinds of bacteria which grow anaerobically, digest the fungi and bacteria of the sludge.
Q.2. Match the following columns and select the correct option. (2020)
Clostridium butylicum is (a bacterium) of butyric acid. Cyclosporin A which is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus Trichoderma polysporum. Monascus purpureus is not a blood cholesterol lowering agent, statins produced by it are been commercialised as blood-cholesterol lowering agents. Aspergillus niger is (a fungus) of citric acid.
Q.3. Which of the following can be used as a biocontrol agent in the treatment of plant disease? (2019)
Trichoderma species are free-living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens.
Fig. Trichoderma Fungi used as bio-controller
Q.4. Select the correct group of biocontrol agents. (2019)
(a) Nostoc, Azospiiillium, Nucleopolyhedrovirus
(b) Bacillus thuringiensis, Tobacco mosaic virus, Aphids
(c) Tiichoderma, Baculovirus, Bacillus thuringiensis
(d) Oscillatoria, Rhizobium, Tiichoderma
Q.5. Which of the following is a commercial blood cholesterol lowering agent? (2019)
(b) Cyclosporin A
Statins are products of fermentation activity of yeast d(onascus purpureas which resemble mevalovate and are competitive inhibitors of 3-hydroxy-f3-methylglutaryl or HMG CoA reductase. This inhibits cholesterol synthesis. Statins are. therefore, used in lowering blood cholesterol, eg., lovastatin, pravastatin, simvastatin.
Q.6. Match the following organisms with the products they produce. (2019)
Select the correct option.
Q.7. A biocontrol agent to be a part of an integrated pest management should be (2019)
(a) species-specific and symbiotic
(b) free living and broad spectrum
(c) narrow spectrum and symbiotic
(d) species-specific and inactive on non-target organisms
Q.8. Conversion of milk to curd improves its nutritional value by increasing the amount of (2018)
(a) vitamin D
(b) vitamin A
(c) vitamin B12
(d) vitamin E
Lactobacillus bacteria convert milk into curd. It produces acids that coagulate and partially digest the milk proteins. A small amount of curd added to the fresh milk as inoculum or starter contains millions of Lactobacillus which at suitable temperature multiply, thereby converting milk to curd which also improves its nutritional value by increasing vitamin B12 content and a number of organic acids.
Fig. Lactobacillus bacteria convert milk into curd
Q.9. Select the mismatch. (2017)
(a) Rhodospirillum - Mycorrhiza
(b) Anabaena - Nitrogen fixer
(c) Rhizobium — Alfalfa
(d) Frankia - Alnus
Rhodospirillum is a free-living nitrogen fixing bacteria. Mycorrhiza is the symbiotic association between ftingi and roots of higher plants. The most common fungal partners of mycorrhiza are Glomus species.
Q.10. Which of the following in sewage treatment removes suspended solids? (2017)
(a) Secondary treatment
(b) Primary treatment
(c) Sludge treatment
(d) Tertiary treatment
Primary or physical treatment is the process of removal of small and large, floating and suspended solids from sewage through two processes of filtration and sedimentation.
Q.11. Which of the following is correctly matched for the product produced by them? (2017)
(a) Methanobacterium : Lactic acid
(b) Penicillium notatum : Acetic acid
(c) Sacchromyces cerevisiae : Ethanol
(d) Acetobacter aceti: Antibiotics
Methanobacterium is useful in the production of biogas. Penicillium notation is used to product, penicillin, an antibiotic. Acetobacter aceti is used to obtain acetic acid.
Q.12. Match column I with column II and select the correct option using the codes given below.
(a) A-(iii), B-(i), C-(ii), D-(iv)
(b) A-(iii), B-(i), C-(iv), D-(ii)
(c) A-(i), B-(iv), C-(ii), D-(iii)
(d) A-(iii), B-(iv), C-(i), D-(ii)
Q.13. Which of the following is wrongly matched in the given table ? (2016)
Clostridium butylicum helps in the production of butyric acid. Candida Upolytica and Geotrichum candidmn help in production of lipases that are added in detergents for removing oily stains from laundry.
Q.14. Which of the following is wrongly matched in the given table ? 
Clostridium butylicum is used for butyric acid production
Q.15. The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, include the (2016)
Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are obligate anaerobic ancient and primitive bacteria. They are involved in methanogenesis.
Q.16. Match the following list of microbes and their importance: (2015)
a - (iii), b - (iv), c - (i), d - (ii)
Q.17. What gases are produced in anaerobic sludge digesters? (2014)
(a) Methane and CO2 only
(b) Methane, Hydrogen Sulphide and CO2
(c) Methane, Hydrogen Sulphide and O2
(d) Hydrogen Sulphide and CO2
Anaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen, used for industrial or domestic purposes to manage waste and/or to release energy. The process of anaerobic digestion produces a biogas, consisting of methane (it will burn), carbon dioxide (it does not burn) and traces of other contaminant gases.