Neomycin is prepared from Steptomyces fradiae. Terramycin is prepared from Streptomyces rimosus. Viridin is prepared from Gliocladium virens. Penicillin is prepared from Penicillium chrysogenum and Penicillium notatum. Answer:(b)

Raw cheese is prepared by coagulating milk using acid or Lactic Acid Bacteria(LAB). This process is called souring. Ripening is carried out to provide cheese with a characteristics texture, flavor and taste. It is carried out with the help of specific microbes. Example: Penicillium camembertii and Penicillium roquefortii. Answer:(b)

Biofertilizers are the organism which bring about nutrient enrichment of the soil. BGA/Anabaena is free living nitrogen fixing cyanobacteria. Answer:(c)

Free living nitrogen fixing bacterium are Azotobacter, Clostridium, Rhodopseudomonas, Rhodospirillum, Chromatium. Answer:(b)

Sugar or sugar based product like molasses is fermented to produce ethanol. Ethanol also act as biofuel Answer:(a)

Antibiotics is a substance produced by microorganism which in low concentration inhibits the growth and metabolic activity of pathogenic organisms without harming the host. The term was coined by Wakesman (1942). Antibiotics is used to cure bacterial disease, not all disease can be cured. Answer:(a)

Bt toxin is obtained from B. thuringiensis, gram positive, soil-dwelling bacterium. Answer:(b)

Green manure plants are young leguminous plants. Example sunn hemp, sweet clover, Egyptian clover. Answer:(d)

Lactobacillus produces lactase which converts milk sugar lactose into lactic acid. It also partially digest milk protein casein. Lactic acid produced coagulates protein to form curd. Answer:(b)

Stirred tank fermenter bioreactors (STBRs) are the reactors most widely employed for culturing of biological agents such as cells, enzymes, or antibodies. They are contractors where the well-mixed among phases is obtained mainly by internal mechanical agitation. It does not control dissolved oxygen. Answer:(b)

Rhizobium is a symbiotic nitrogen fixing bacteria. It has mutually beneficial relation with leguminous plants. Root nodules has leghaemoglobin. Soybean belongs to leguminous plants. Answer:(b)

Organic farming is an agricultural system that uses fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. Glomus being a mycorrhizal component, earthworm being a vermicompost and Oscillatoria being a nitrogen fixing blue green algae can be used in organic farming. Snail cannot be a component of organic farming. snails and slugs are primarily pests of seedlings and herbaceous plants. They are also serious pests of turfgrass seedlings and ripening fruits that are close to the ground, such as strawberries and tomatoes. Answer:(c)

Yeast species used in alcoholic fermentation are Saccharomyces cerevisiae (Brewer’s yeast), S. ellipsoidens (wine yeast), S. sake (Sake yeast) and S. pireformis (Ginger beer/ale yeast). Answer:(a)

Swiss cheese has large holes produced by carbon dioxide given out by bacterium Propionibacterium sharmanii Answer:(c)

Rene Dubois was first to produce an antibiotic named tyrothricin from Bacillus brevis. However, first antibiotic is generally associated with the name of Alexander Fleming when he discovered penicillin from Penicillium notatum. Answer:(b)

Nitrogen fixing enzyme nitrogenase present in legume root nodules function at low oxygen concentration. Low oxygen concentration is provided by leghaemoglobin. Leghaemoglobin is known as scavenger of oxygen. Answer:(a)

The key characteristics of organic farming include 1 Protecting the long term fertility of soils by maintaining organic matter levels, encouraging soil biological activity, and careful mechanical intervention; 2 Providing crop nutrients indirectly using relatively insoluble nutrient sources which are made available to the plant by the action of soil micro-organisms; 3 Nitrogen self-sufficiency through the use of legumes and biological nitrogen fixation, as well as effective recycling of organic materials including crop residues and livestock manures; 4 Weed, disease and pest control relying primarily on crop rotations, natural predators, diversity, organic manuring, resistant varieties and limited (preferably minimal) thermal, biological and chemical intervention; 5 The extensive management of livestock, paying full regard to their evolutionary adaptations, behavioural needs and animal welfare issues with respect to nutrition, housing, health, breeding and rearing; 6 Careful attention to the impact of the farming system on the wider environment and the conservation of wildlife and natural habitats. Organic farming is an agricultural system that uses fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. Biological pest control, mixed cropping and the fostering of insect predators are encouraged. Answer:(d)

Answer:(d)

Xanthomonas campestris is an aerobic, Gram-negative rod known to cause the black rot in crucifers by darkening the vascular tissues. Remaining three are used as biocontrol agents for pathogens and pest. Answer:(a)

Baculoviruses are pathogens that attack insects and other arthropods. The majority of baculoviruses used as biological control agents are in the genus Nucleopolyhedrovirus. These viruses are excellent candidates for species-specific, narrow spectrum insecticidal applications. They have been shown to have no negative impacts on plants, mammals, birds, fish or even on non-target insects. This is especially desirable when beneficial insects are being conserved to aid in an overall integrated pest management (IPM) programme, or when an ecologically sensitive area is being treated. Answer:(d)

Answer:(c)

Pasteurization is a process of preservation of milk, wine and other liquids by heating for a short period and then cooling rapidly. The most common method of milk preservation for 2-5 days is heating it at 72°C for 15 seconds or 63°C for 30 minutes. Answer:(b)

A small quantity of baker’s yeast (Saccharomyces cerevisiae) is added to dough. The yeast acts on glucose to form bubbles of ethyl alcohol and carbon dioxide. This makes bread soft and spongy. Answer:(c)

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)

Vesicular-arbuscular mycorrhiza (VAM) is formed by the symbiotic association between certain phycomycetous fungi and angiosperm roots. Vesicular Arbuscular Mycorrhizal (VAM) is a fungus which has the ability to dissolve the phosphates found in abundance in the soil. Apart from increasing the availability of phosphorus, VAM provides the plants with the necessary strength to resist disease germs and unfavourable weather conditions. Answer:(b)

The vermicomposting process was optimal at pH (6.5-7.7), temperature (19-25&dgeC) and moisture content (27.68-52.41%). pH should be closer to neutral. Answer:(a)

Yeast produces enzyme zymase. Zymase converts glucose into ethanol and carbon dioxide Answer:(a)

Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. A small amount of curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperatures multiply, thus converting milk to curd, which also improves its nutritional quality by increasing vitamin B12. In our stomach too, the LAB play very beneficial role in checking disease causing microbes. Answer:(c)

Aspergillus niger can ferment sugar to produce citric acid. Citric acid is preservative and flavoring agent. It is also used in medicines, dyeing and inks. REFERENCE: NCERT class 12 biology page 183 Answer:(a)

Methanogens work on organic acid produced in anaerobic sludge digesters. Methanogen produces methane, carbon dioxide, hydrogen sulphide. These mixture is called marsh gas or biogas. Answer:(d)