In the production of various food items, microbes play an essential role. One example is the fermentation process used in the preparation of bread, yogurt, and cheese. In bread-making, Saccharomyces cerevisiae (baker's yeast) is used for fermentation. This yeast ferments sugars in the dough, releasing carbon dioxide gas that causes the dough to rise, leading to the soft texture of the bread. Similarly, in yogurt production, Lactobacillus bacteria convert lactose into lactic acid, which thickens the milk and gives yogurt its characteristic texture and flavor.
Saccharomyces cerevisiae is used in bread-making primarily for:
Answer: B) Carbon dioxide production
Lactobacillus bacteria are used in yogurt production because they:
Answer: A) Produce lactic acid
The fermentation process in food production involves:
Answer: A) Conversion of glucose into alcohol and carbon dioxide
Which of the following is NOT a product made using microorganisms?
Answer: C) Butter
Microorganisms play a significant role in the natural process of biodegradation, where organic matter is broken down by bacteria, fungi, and other microbes. This is particularly important in sewage treatment and the breakdown of pollutants. In sewage treatment, aerobic bacteria are used to degrade organic matter, turning harmful substances into harmless ones, while anaerobic bacteria help in the final stage of the treatment, producing biogas that can be used as an energy source.
In sewage treatment, the role of aerobic bacteria is to:
Answer: B) Break down organic matter
Which of the following is a byproduct of anaerobic bacteria in the sewage treatment process?
Answer: C) Methane (biogas)
Biodegradation refers to the breakdown of:
Answer: B) Organic matter by microorganisms
One of the advantages of biogas production from sewage treatment is:
Answer: A) It reduces environmental pollution
Microorganisms are used extensively in the field of medicine for the production of important antibiotics and other therapeutic products. Penicillin, produced by the fungus Penicillium notatum, is one of the first antibiotics discovered and has saved millions of lives by killing harmful bacteria. Another example is the use of insulin produced by genetically modified bacteria. These bacteria are engineered to carry the gene for insulin production, making insulin readily available for treating diabetes.
Penicillin, an important antibiotic, is derived from:
Answer: C) Fungi
Insulin used for treating diabetes is produced by:
Answer: B) Bacteria
The use of genetically modified bacteria for insulin production is an example of:
Answer: A) Genetic engineering
Which of the following antibiotics is produced by the fungus Penicillium?
Answer: B) Penicillin
Biofertilizers are substances that contain living microorganisms which help in improving soil fertility by fixing nitrogen and decomposing organic matter. Rhizobium is a bacterium that forms symbiotic relationships with leguminous plants, fixing atmospheric nitrogen into a form usable by the plant. Similarly, Azotobacter and Azospirillum are free-living bacteria that also fix nitrogen in the soil, reducing the need for chemical fertilizers.
Rhizobium bacteria are used in biofertilizers because they:
Answer: A) Fix nitrogen in the soil
Which of the following bacteria is known for nitrogen fixation in leguminous plants?
Answer: B) Rhizobium
The use of biofertilizers helps in:
Answer: A) Reducing the need for chemical fertilizers
Azotobacter and Azospirillum are examples of:
Answer: B) Free-living nitrogen-fixing bacteria
Biocontrol refers to the use of natural predators, parasites, or pathogens to control pests. One example is the use of Trichoderma, a soil fungus, which is used to control various plant diseases caused by other fungi. Another example is the use of Bacillus thuringiensis (Bt), a bacterium that produces toxins harmful to insect pests. The use of Bt in genetically modified crops like Bt cotton has helped in reducing the use of chemical insecticides.
Trichoderma, used in biocontrol, helps in:
Answer: B) Controlling fungal diseases in plants
Bacillus thuringiensis (Bt) is primarily used in biocontrol because it:
Answer: A) Produces toxins that are harmful to insect pests
Biocontrol as a method for pest management is advantageous because it:
Answer: A) Reduces the use of synthetic pesticides
Bt cotton has been genetically modified to:
Answer: B) Produce a toxin that kills insect pests