Vermicomposting is composting of organic matter with the help of earthworms. Worm castings are rich of phosphorus, nitrogen, calcium and humic acid and other minerals. Humic acids chemically change the fixation properties of the soil, with benefits such as: Neutralizes both acid and alkaline soils; regulates the pH-value of soils. Improves and optimizes the uptake of nutrients and water by plants. Increases buffering properties of soil. 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)

Root of legumes is in mutual beneficial association with Rhizobium. This association helps legumes fix atmospheric nitrogen to ammonia. Answer:(b)

Apergillus niger, Mucor species and yeast(when medium is deficient in Fe and Mn) can ferment sugar to produce citric acid. 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:(b)

microbial biocontrol agents that can be introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (often written as Bt) Answer:(d)

Broad spectrum antibiotics are the antibiotics which can kill or destroy a number of pathogens that belongs to different groups with different structures and wall composition. Answer:(b)

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)

The main ingredient of biogas is methane (50-70%). Other components are carbon dioxide (25-35%), hydrogen(1-5%), nitrogen (2-7%) and hydrogen sulphide(traces). Answer:(d)

Mycorrhiza is a mutually beneficial relationship between fungus and roots of higher plants. Mycorrhiza helps in absorption of water, minerals from organic matter and protection from soil borne pathogenic fungi. Answer:(b)

Mycorrhiza is a mutually beneficial relationship between fungus and roots of higher plants. Mycorrhiza helps in absorption of water, minerals from organic matter and protection from soil borne pathogenic fungi. Answer:(b)

Bordeaux mixture—a combination of copper sulfate, lime, and water—is an effective fungicide and bactericide that has been used for decades to control diseases of fruit and nut trees, vine fruits, and ornamental plants. The Bordeaux mixture fungicide (copper sulfate and lime), discovered accidentally in 1882, was used successfully against vine downy mildew; this compound is still employed to combat it and potato blight Answer:(d)

Bordeaux mixture—a combination of copper sulfate, lime, and water—is an effective fungicide and bactericide that has been used for decades to control diseases of fruit and nut trees, vine fruits, and ornamental plants Answer:(c)

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)

Nostoc and legumes are biofertilizers and increase soil fertility. Bacillus and Penicillium are used in synthesis of antibiotics. Answer:(b)

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

Trichoderma harzianum is a fungus that is also used as a fungicide. It is used for foliar application, seed treatment and soil treatment for suppression of various disease causing fungal pathogens Answer:(b)

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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:(b)

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:(b)

Rhizobium in symbiotic relation with root of leguminous plants fix atmospheric nitrogen. Nitrogen is converted into ammonia. So, if wheat field is inoculated with Rhizobium will have no effect on soil nitrogen. It is possible only with legumes. Answer:(c)

Streptomyces fradiae produces Neomycin which used as antibacterial against gram negative bacilli and some gram positive bacteria. Aureomycin is produced by Streptomyces aureofaciens. Erythromycin is produced by S. erythreus. Terramycin is produced by S. rimosus. Answer:(b)

Alternate source of proteins for animal and human nutrition is Single Cell Protein(SCP). It is protein rich microbial biomass and has all the essential amino acids. Algae, yeast and some fungus are raised as SCP. Answer:(a)

The brown planthopper (BPH), Nilaparvata lugens (Hemiptera: Delphacidae) is a planthopper species that feeds on rice plants (Oryza sativa L.). Answer:(a)

The Nobel Prize in Physiology or Medicine 1945 was awarded jointly to Sir Alexander Fleming, Ernst Boris Chain and Sir Howard Walter Florey "for the discovery of penicillin and its curative effect in various infectious diseases." Answer:(c)

Zymase enzyme produced by yeast converts glucose into alcohol and in this process carbon dioxide is also obtained as by-product. Answer:(c)

Biogas also known as marsh gas is produced by anaerobic bacteria. Anaerobic bacteria breakdown organic matter into monomers and then into organic acids. Organic acids are then converted into mthane, hydrogen sulphide and carbon dioxide by methanogens. Supply of oxygen will hinder process of anaerobic bacteria and thus have negative effect. Answer:(b)

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Single cell protein typically refers to source of mixed protein extracted from pure or mixed culture of algae, yeast, fungi or bacteria. The most common source of single cell protein are single celled yeast e.g. Candida utilis and filamentous fungus like Fusarium graminearum. Answer:(b)