Streptomycetes are characterised by a complex secondary metabolism. They produce over two-thirds of the clinically useful antibiotics of natural origin e.g., neomycin, cypemycin, grisemycin, bottromycins and chloramphenicol. Streptomyces griseus produces more than 41 antibiotics while Bacillus subtilis can give about 60 antibiotics Answer:(c)

Aspergillus niger (a fungus) of citric acid, Acetobacter aceti (a bacterium) of acetic acid; Clostridium butylicum (a bacterium) of butyric acid and Lactobacillus (a bacterium) of lactic acid. Reference NCERT text book 12th Page 183, 10.2.3 Chemicals, Enzymes and other Bioactive Molecules Answer:(b)

Activated sludge is take into anaerobic sludge digester. Here, anaerobic microbes act upon organic matter to first produce monomers and then organic acids. Methanogens then convert organic acids into a mixture of gases like methane, hydrogen sulphide and carbon dioxide. Answer:(b)

Microbes are used in production of several household and industrial products – Lactobacillus – Production of curd Saccharomyces cerevisiae – Bread making Aspergillus niger – Citric acid production Acetobacter aceti – Acetic acid Answer:(b)

Fungs Trichoderma, Baculoviruses (NPV) and Bacillus thuringiensis are used as biocontrol agents. Rhizobium, Nostoc, Azospirillum and Oscillatoria are used as biofertilisers, whereas TMV is a pathogen and aphids are pests that harm crop plants. Answer:(b)

Statin is obtained from a yeast (Fungi) called Monascus purpureus. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol. Answer:(d)

Fungus Trichoderma is a biological control agent being developed for use in the treatment of plant diseases. Answer:(a)

Answer:(a)

Organic matter readily decomposes due to bacteria and other micro-organism. These micro-organism consumes lot of dissolved oxygen. This causes mortality of fishes and other aquatic creatures. Answer:(d)

Citric acid is produced by Aspergillus niger. Butyric acid is produced by Clostridium butyricum. Statins are synthesized by activity of yeast Monascus purpureus. Cyclosporin A is synthesized by fungus Trichoderma polysporum. Answer:(d)

Clostridium acetobutylicum was metabolically engineered for highly selective butyric acid production. a → ii Cyclosporine A is widely produced by submerged fermentation of aerobic fungi identified as Trichoderma polysporum. b → i Manescus purpureus is a yeast used commercially in the production of blood cholesterol lowering statins. c → iv Aspergillus niger is a fungal microbe of great industrial importance. This mold is used extensively in the production of citric acid and in the production of several enzymes such as amylases, pectinases, and proteases. d → iii Answer:(d)

Saccharomyces cerevisiae is commonly called Brewer’s yeast. It causes fermentation of carbohydrates producing ethanol. Acetobacter aceti produces acetic acid from ethanol. Methanobacterium produces methane and is present in cow's gut. Penicillium notatum is the first Penicillium fungi used for the isolation of penicillin antibiotics, which is used for the treatment of Gram-positive bacteria. Answer:(d)

Rhodospirillum is anaerobic, free living nitrogen fixer.Mycorrhiza is a symbiotic relationship between fungi and roots of higher plants. Answer:(b)

Saccharomyces cerevisiae is commonly called Brewer’s yeast. It causes fermentation of carbohydrates producing ethanol. Statins are synthesized by activity of yeast Monascus purpureus. It is used for lowering LDL cholesterol level. Fungus Trichoderma polysporum produces cyclosporin A. Cyclosporin A has immunosuppressive property as it inhibits activation of T cell response to transplanted organs. Swiss cheese has large holes produced by carbon dioxide given out by bacterium Propionibacterium sharmanii. Answer:(b)

Paenibacillus polymyxa, also known as Bacillus polymyxa, is a Gram-positive bacterium capable of fixing nitrogen. It is found in soil, plant tissues, marine sediments and hot springs Answer:(b)

During cellulose fermentation by anaerobic bacteria in rumen and reticulum, cellulose is mainly changed to volatile fatty acids Answer:(d)

Devine and Collego derived from the fungal spores. Devine was first mycoherbicide and another mycoherbicide was Collego. Its controls growth of the milk weed vines in citrus orchards and growth the northern jointvetch growing in rice fields respectively. Answer:(b)

Saccharomyces cerevisiae also known as brewer’s yeast is used in production of alcohol. Torulopsis utilis is a species of yeast. It is an inactive form of yeast and widely used as a flavouring agent in processed foods and pet foods. Clostridium botulinum is a bacterium that produces dangerous toxins (botulinum toxins) under low-oxygen conditions. Botulinum toxins are one of the most lethal substances known. Botulinum toxins block nerve functions and can lead to respiratory and muscular paralysis. Leuconostoc species are heterofermentative, Gram-positive cocci. They produce flavor compounds such as diacetyl and acetoin, and some strains produce exopolysaccharides. Leuconostoc mesenteroides subsp. cremoris is used in the production of cottage and cream cheese and cultured milks. Answer:(a)

Azolla pinnata is a small aquatic fern inoculated to rice fields of south-east Asian countries. It contains symbiont Anabaena in its leaf cavities. Increase in yield is more than 50%. Answer:(b)

Baker's yeast is of the species Saccharomyces cerevisiae, and is the same species (but a different strain) as the kind commonly used in alcoholic fermentation, which is called brewer's yeast. Baker's yeast is the common name for the strains of yeast commonly used in baking bread and other bakery products, serving as a leavening agent which causes the bread to rise by converting the fermentable sugars present in the dough into carbon dioxide and ethanol. Answer:(a)

Azolla pinnata is a small aquatic fern inoculated to rice fields of south-east Asian countries. It contains symbiont Anabaena in its leaf cavities. Increase in yield is more than 50%. Answer:(a)

Bacillus subtilis is used in synthesis of enzyme protease. Streptococcus lactis produces lactic acid. Bacillus thuringiensis synthesize different insecticidal proteins named Cry, Vip, and Cyt that are able to kill different insect orders, or nematodes. These proteins have been extensively used in insect control practices in agriculture. Lactobacillus acidophilus help restore the normal balance of intestinal bacteria. This product has been used for diarrhea and other stomach/intestinal problems. Answer:(c)

Terramycin is antibiotics used for intestinal and urinary infections. It is synthesized from Streptomyces aureofaciens. Answer:(c)

Colour	Area of biotech activities
Red	Health, medical
Yellow	Food, nutritional science
Blue	Aquaculture, coastal, marine
Green	Agricultural, environmental
White	Gene-based bioindustries
Grey	Classical fermentation and bioprocess technology

Answer:(c)

Nitrogen fixation, any natural or industrial process that causes free nitrogen (N2), which is a relatively inert gas plentiful in air, to combine chemically with other elements to form more-reactive nitrogen compounds such as ammonia, nitrates, or nitrites. Answer:(d)

Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important biofertiliser. Blue green algae also add organic matter to the soil and increase its fertility Answer:(a)

Penicillin is derived from Penicillium chrysogenum and Penicillium notatum. Answer:(b)

An antibiotics is a substance produced by a microorganism which in low concentration inhibits the growth and metabolic activity of pathogens without harming the host. The term was coined by Waksman(1942). Antibiotics work against bacteria and hence cannot cure all disease Answer:(a)

Azadirachtin, a chemical compound belonging to the limonoid group, is a secondary metabolite present in neem seeds. It is natural insecticide and is used as repellent. Answer:(b)

In case of wines 10-27% alcohol content is achieved through refinement and concentration. There is no need for distillation. Distillation is carried out in other cases like gin, brandy, rum. Distillation is done to increase concentration of alcohol content. Thus, distillation will have no action on nature of wine. Answer:(c)