The pyrethrins are a class of organic compounds normally derived from Chrysanthemum cinerariifolium that have potent insecticidal activity by targeting the nervous systems of insects Answer:(d)

rennin, also called chymosin, protein-digesting enzyme that curdles milk by transforming caseinogen into insoluble casein; it is found only in the fourth stomach of cud-chewing animals, such as cows. It is used in production of cheese. Answer:(a)

Biofertilizers are organisms which bring about nutrient enrichment of the soil. They are of three types- nitrogen fixing bacteria, nitrogen fixing cyanobacteria and mycorrhiza. Answer:(d)

Vinegar is 10-13% ripened acetic acid. Initially molasses or sugar solution is allowed to undergo alcoholic fermentation by yeast. As soon as 10-12% alcohol is formed, the liquid is filtered to remove yeast. It is aerated and inoculated with Acetobacter aceti. This microbe produces acid. When 10-13% acetic acid content is achieved, the liquid is filtered. The filtrate is allowed to ripen till the disagreeable smell disappears. It is pasteurized and called vinegar. Answer:(b)

Biofertilizers are organisms which bring about nutrient enrichment of the soil. Rhizobia is a symbiotic nitrogen fixing bacteria. Rhizobium in symbiotic relation with root of leguminous plants fix atmospheric nitrogen. Other options are part of organic farming. Answer:(b)

Green manure: It is ploughed back young leguminous crop like Sesbania aculeate, Sesbania rostrate (both root and stem nodules), Crotalaria juncea (Sunn hemp), Cyamopsis tetragonoloba, etc Answer:(b)

Leghaemoglobin is found in the nodules of leguminous plants. The main functions of leghemoglobin are (1) to facilitate oxygen supply to the nitrogen fixing bacteria and (2) to protect the enzyme, nitrogenase from being inactivated by oxygen. Answer:(b)

Worm castings are rich of phosphorus, nitrogen, calcium and humic acid and other minerals Answer:(d)

Agrobacterium tumefaciens is a plant pathogen with the capacity to deliver a segment of oncogenic DNA carried on a large plasmid called the tumor-inducing or Ti plasmid to susceptible plant cell. Answer:(d)

A biological control being developed for use in the treatment of plant disease is the fungus Trichoderma. Trichoderma species are free-living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens. Answer:(c)

Cheese, is one of the oldest food items in which microbes were used. Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity coming from the microbes used. For example, the large holes in ‘Swiss cheese’ are due to production of a large amount of CO2 by a bacterium named Propionibacterium sharmanii. The ‘Roquefort cheese’ are ripened by growing a specific fungi on them, which gives them a particular flavour. Answer:(d)

Vermicompost is the product of the decomposition process using various species of worms, usually red wigglers, white worms, and other earthworms, to create a mixture of decomposing vegetable or food waste, bedding materials, and vermicast or worm cast. Answer:(a)

Yeast produces three enzymes- amylase, maltase and zymase complex. Amylase converts small quantity of starch into maltose. Maltase converts maltose to glucose. Zymase complex acts on glucose to produce ethanol. Answer:(a)

Single cell protein typically refers to source of mixed protein extracted from pure or mixed culture of algae, yeast, fungi or bacteria (microorganism) Answer:(c)

Curd, milk, cheese and butter are products of raw milk. All these products are produced using strains of Lactobacillus and Streptococcus. In above options only streptococcus is mentioned, so most appropriate option is (a). Answer:(a)

Yogurt is fermented milk. Cheese is a dairy product and produced in wide ranges of flavors, textures and forms by coagulation of the milk protein casein. Both products are produced by process of fermentation. Answer:(c)

Single cell protein typically refers to source of mixed protein extracted from pure or mixed culture of algae, yeast, fungi or bacteria (microorganism) Answer:(b)

Beer’s nutrient medium is Barley (Hordeum vulgare) grain which have been semi germinated and crushed to form malt. Before inoculation with yeast, the infusion of malt is treated with hops (Humulus lupulus) to provide flavor, colour and stability. Answer:(b)

Agrobacterium tumefaciens is a plant pathogen with the capacity to deliver a segment of oncogenic DNA carried on a large plasmid called the tumor-inducing or Ti plasmid to susceptible plant cells. Answer:(c)

Worm castings are rich of phosphorus, nitrogen, calcium and humic acid and other minerals. Answer:(d)

In 1928, Alexander Fleming noticed that the growth of staphylococcus colonies growing near a contaminating mold colony was disrupted. The following year, he published a paper describing the mold as Penicillium notatum and terming the active compound penicillin Alexander Fleming discovered penicillin from Penicillium notatum. Answer:(a)

Secondary treatment involves biological process of microbial degradation of organic matter. Answer:(a)

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:(b)

Aspergillus niger synthesis citric acid. Saccharomyces cerevisiae produces ethanol from glucose. Clostridium butyricum produces butyric acid. Trichoderma polysporum produces cyclosporin A which is an immunosuppressant. Monascus purpureus synthesize statins which helps in lowering cholesterol level. Answer:(c)

Nostoc is free living nitrogen fixing cyanobacteria which increase nitrogen content of moist soil. Mycorrhiza is a mutually beneficial relationship between fungus and roots of higher plants. Mycorrhiza helps in absorption of water, minerals. Agrobacterium is used to to transfer genes to plants and fungi is used in biotechnology, in particular, genetic engineering for plant improvement. Rhizobium is a symbiotic nitrogen fixing bacteria forms mutual beneficial association with root nodules of legumes. Answer:(b)

Rhizobium is a symbiotic nitrogen fixing bacteria. It has mutually beneficial relation with leguminous plants. Gram belongs to leguminous plants. Answer:(a)

Lactic acid is used in production of yogurt. Lactic acid are produced by bacteria like Streptococcus lactis, Streptococcus thermophiles and Lactobacillus bulgaricus. Acetobacter aceti produces acetic acid. Answer:(d)

Biocontrol refers to the use of biological methods for controlling plant diseases and pest. It is a holistic approach that seeks to develop an understanding of the webs of interaction between the myriad of organisms that constitute the field fauna and flora. The use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides Answer:(c)

Methanobacterium is an anaerobic bacteria found in rumen of cattle. Biogas commonly called as gobar gas is mixture of methane, carbon dioxide, hydrogen sulphide, nitrogen and hydrogen. Methane is main ingredient. Biogas is produced by the activity of anaerobic bacteria on organic waste. Answer:(c)

Advantages of vermicompost • Vermicompost helps improve soil structure, texture, porosity, water holding capacity, drainage, and aeration and reduce erosion. • It improves plant growth by enabling the growth of new shoots and leaves, thereby increasing productivity. • It helps to neutralize the pH of the soil. • Vermicompost enhances the soil’s microbial activity and adds beneficial microbes, lowers the pest and disease incidence. • It is easy to apply and handle, economical and does not have a foul odor. • It is free from any pathogens or harmful materials. • It contains several micro and macronutrients, vitamins, enzymes and hormones like auxins and gibberellins. Answer:(b)