Maharashtra Board Class 10 Science Chapter 7 Introduction to Microbiology Solutions

Std 10 Science Part 2 Chapter 7 Introduction To Microbiology Question Answer Maharashtra Board

Question 1. Rewrite the following statements using correct of the options and explain the completed statements. (gluconic acid, coagulation, amino acid, 4% acetic acid, clostridium, lactobacilli)
a. Process of - of milk proteins occurs due to lactic acid.
Answer: Process of Coagulation of milk proteins occurs due to lactic acid. Explanation: The lactobacilli are the bacteria carrying out fermentation of the milk. In this process, the lactose sugar in the milk is converted into lactic acid. This lactic acid causes coagulation of the proteins present in the milk.
In simple words: Lactic acid, produced by lactobacilli during fermentation, causes milk proteins to coagulate by converting lactose into lactic acid.

🎯 Exam Tip: Understanding the role of lactobacilli in milk fermentation and protein coagulation is key to explaining this process.

 

b. Harmful bacteria like - in the intestine are destroyed due to probiotics.
Answer: Harmful bacteria like Clostridium in the intestine are destroyed due to probiotics. Explanation: In probiotics, there are lactobacilli which are useful. They control other bacteria present in the alimentary canal and also their metabolism. These bacteria thus stop the action of Clostridium which is a harmful bacteria.
In simple words: Probiotics contain beneficial lactobacilli that inhibit harmful bacteria like Clostridium in the intestine, promoting a healthy gut environment.

🎯 Exam Tip: Focus on the beneficial role of probiotics in suppressing harmful gut microbes for good scores.

 

c. Chemically, vinegar is -
Answer: Chemically, vinegar is 4% Acetic acid. Explanation: Chemically vinegar is 4% acetic acid. It is a good preservative of the food and thus while using it as additive to the food, it is called vinegar.
In simple words: Vinegar is essentially a 4% solution of acetic acid, commonly used as a food preservative due to its chemical properties.

🎯 Exam Tip: Remembering the chemical composition and primary use of vinegar is important for this type of question.

 

d. Salts which can be used as supplement of calcium and iron are obtained from - acid.
Answer: Salts which can be used as supplement of calcium and iron are obtained from Gluconic acid. Explanation: The microbe Aspergillus niger is used on the source material of glucose and corn steep liquor to produce amino acid called Gluconic acid. Gluconic acid is used for the production of minerals used as supplement for calcium and iron.
In simple words: Gluconic acid, produced by Aspergillus niger, is a source from which salts used as calcium and iron supplements are obtained.

🎯 Exam Tip: Connect specific microbial products like Gluconic acid to their industrial and nutritional applications.

 

Question 2. Match the pairs.

'A' group	'B' group
(1) Xylitol	(a) Pigment
(2) Citric acid	(b) To impart sweetness
(3) Lycopene	(c) Microbial restrictor
(4) Nycin	(d) Protein binding emulsifier
	(e) To impart acidity

Answer:(1) Xylitol - To impart sweetness (2) Citric acid - To impart acidity (3) Lycopene - Pigment (4) Nycin - Microbial restrictor.
In simple words: This match identifies Xylitol for sweetness, Citric acid for acidity, Lycopene as a pigment, and Nycin as a microbial restrictor.

🎯 Exam Tip: For match-the-pairs, ensure you know the specific function or category of each substance to avoid common errors.

 

Question 3. Answer the following: a. Which fuels can be obtained by microbial processes? Why is it necessary to increase the use of such fuels?
Answer:• Microbial anaerobic decomposition of urban agricultural and industrial waste forms the gaseous fuel in the form of methane gas. • Alcohol is another clean form of energy which is used in the form of ethanol. It is obtained by the fermentation of molasses by treating it with Saccharomyces-yeast. • By photoreduction of water with the help of bacteria, hydrogen gas is released in the process of bio-photolysis of water. This hydrogen gas is said to be the fuel of the future. • The conventional fuels are exhaustible. After few hundred years, they will be over completely. Moreover, these fossil fuels cause lot of air pollution due to emission of carbon dioxide. The fuels obtained by the microbial processes are not polluting. Therefore, it is necessary to increase the use of eco-friendly fuels.
In simple words: Microbial processes yield methane, ethanol, and hydrogen gas as fuels. Increasing their use is crucial because they are eco-friendly, non-polluting alternatives to exhaustible fossil fuels that cause significant air pollution.

🎯 Exam Tip: List at least three microbially produced fuels and clearly articulate the environmental advantages of switching to them.

 

b. How can the oil spills of rivers and oceans be cleaned?
Answer:• The oil spills in rivers or oceans are caused by crude oil or petroleum hydrocarbons. • This crude oil is highly toxic to the flora and fauna of the aquatic environment. • By using mechanical means the oil spill can be removed, but this is very difficult. • The biological way to remove this pollution is done by using culture of microbes like Pseudomonas spp. and Alcanovorax borkumensis. • They have the ability to destroy the pyridines and other chemicals present in the hydrocarbons. • These bacteria are called as hydrocarbono-clastic bacteria (HCB) which decompose the hydrocarbons and bring about the reaction of carbon with oxygen. • In the process CO2 and water are formed. In this way the oil spills are cleaned, by releasing HCB at the place of oil spills.
In simple words: Oil spills can be cleaned biologically using hydrocarbono-clastic bacteria like Pseudomonas spp. and Alcanovorax borkumensis, which decompose toxic hydrocarbons into carbon dioxide and water, offering an effective alternative to difficult mechanical methods.

🎯 Exam Tip: Name specific bacteria involved in bioremediation of oil spills and describe their mechanism of action (decomposing hydrocarbons into CO2 and water).

 

c. How can the soil polluted by acid rain be made fertile again?
Answer:• The soil polluted by the acid rain is made fertile again by using bacteria. • Acidophillium spp. and Acidobacillus ferroxidens are the bacteria which have the capacity to use sulphuric acid as their energy source. • Since this sulphuric acid present in the acid rain, can be controlled by these bacteria. • In this way, bacteria can control the soil pollution occurring due to acid rain, making the soil fertile again.
In simple words: Soil polluted by acid rain can be restored using bacteria like Acidophillium spp. and Acidobacillus ferroxidens, which consume sulphuric acid as an energy source, thereby reducing acidity and restoring soil fertility.

🎯 Exam Tip: Identify the types of bacteria that thrive on sulfuric acid and explain how their metabolic activity helps neutralize acid rain effects on soil.

 

d. Explain the importance of bio pesticides in organic farming.
Answer:• By using bio pesticides, soil pollution is minimized. Otherwise by using chemical pesticides and fertilizers there is large scale soil pollution. • When chemical pesticides are used in agriculture, there is contamination of soil by fluoroacetamide - like chemicals. • These are harmful to other plants, animals as well as for-human beings. They may cause skin diseases in humans. • By using bacterial and fungal toxins the pests and pathogens can be destroyed. Such toxins are directly incorporated in the plant materials. E.g. Spinosad is a biopesticide produced as a by-product of fermentation.
In simple words: Biopesticides are crucial in organic farming because they minimize soil pollution caused by harmful chemical pesticides, protecting plants, animals, and humans by naturally controlling pests through bacterial and fungal toxins.

🎯 Exam Tip: Highlight the environmental benefits (reduced pollution) and health benefits (less chemical exposure) of biopesticides compared to chemical ones.

 

e. What are the reasons for increasing the popularity of probiotic products?
Answer:• Probiotic substances are mostly milk products containing live bacteria. Such probiotics are very good for health. • The useful colonies of bacteria are produced in the alimentary canal of human beings due to the probiotics. • Probiotics decrease the population of harmful microbes like. Clostridium from our digestive tract. • The immunity is enhanced due to regular intake of probiotics in the diet. • The ill-effects of harmful substances formed during metabolic activities are reduced by the probiotics. • If someone takes the antibiotic treatment, then his or her useful intestinal bacterial flora becomes inactive or is eradicated. In such cases, probiotics restore the bacterial flora and make the person well again.
In simple words: Probiotics are popular because they introduce beneficial bacteria to the gut, improving digestion, boosting immunity, reducing harmful microbes, and helping restore healthy bacterial flora after antibiotic use.

🎯 Exam Tip: Focus on the direct health benefits like improved digestion, boosted immunity, and gut flora restoration as key reasons for probiotic popularity.

 

f. How the bread and other products produced using baker's yeast are nutritious?
Answer:• In order to make the bread the baker's yeast - Saccharomyces cerevisiae is added to the flour for the fermentation process. • In commercial bakery, compressed yeast is used while in domestic settings dry, granular form of yeast is used. • The flour prepared by using commercial yeast contains various useful contents like carbohydrates, fats, proteins, various vitamins, and minerals. • The anaerobic fermentation also increases the nutritive content of the flour. • Due to this, bread and other products produced with the help of yeast become nutritive.
In simple words: Baker's yeast (Saccharomyces cerevisiae) enriches bread and other products by fermenting flour, adding carbohydrates, fats, proteins, vitamins, and minerals, thereby increasing their overall nutritive value.

🎯 Exam Tip: Explain how yeast fermentation adds essential nutrients and improves the nutritional profile of baked goods.

 

g. Which precautions are necessary for proper decomposition of domestic waste?
Answer: The domestic waste should be properly segregated into biodegradable (wet waste) and non-biodegradable (dry waste). After segregation, these wastes should be stored separately into two different containers. The non-biodegradable substances should he either reused or sent for recycling. The biodegradable substances are decomposed naturally. The decomposition process can be done at house-hold level too in a pot or a tank. This decomposition will yield a rich manure. The pot should be covered by a thin layer of soil and it should be kept in a dark but airy place. The non-biodegradable things such as plastic articles, glass pieces, metal objects, unused 5 medicines, e-waste should never be thrown in wet wastes. The toxic substances and the insecticides if added to wet waste, will never allow the natural decomposition process. Therefore, only after taking proper precautions we can aim at proper decomposition of domestic wastes.
In simple words: Proper domestic waste decomposition requires segregation into biodegradable and non-biodegradable waste, separate storage, and ensuring no toxic or non-degradable items contaminate the wet waste to allow natural microbial breakdown.

🎯 Exam Tip: Emphasize the importance of waste segregation and avoiding contaminants for efficient microbial decomposition and manure production.

 

h. Why is it necessary to ban the use of plastic bags?
Answer: Plastic is a non-biodegradable substance. It cannot be degraded back into its original constituents. It remains just like that for many hundreds of years. It causes solid waste pollution in any environment wherever it is thrown indiscriminately. If burnt, it releases very toxic gases. If dumped in landfills it obstructs the other decomposition processes. If thrown in water bodies, it causes harm to aquatic life. Cattle graze on plastic unknowingly and are killed by it as it clogs inside their alimentary canal. The gutters and rain water drains get clogged due to plastic bags and this causes cities to submerge in water during heavy rains. Nowadays, the fishermen get more than half of plastic if they cast their net in the sea. People use the plastic bags indiscriminately without any thought towards their environmental impact. There are better alternatives for plastic bags such as cloth bags which can be reused again and again. Therefore, it is absolutely necessary to ban the use of plastic bag.
In simple words: Banning plastic bags is necessary because they are non-biodegradable, causing widespread environmental pollution, harming aquatic and terrestrial life, clogging drainage systems, and releasing toxic gases when burned.

🎯 Exam Tip: List multiple negative environmental and ecological impacts of plastic bags to justify the ban, including non-biodegradability, pollution, and harm to wildlife.

 

Question 4. Complete the following conceptual picture.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक वैचारिक चित्र है जो अपशिष्ट जल के प्रबंधन को दर्शाता है। इसमें दिखाया गया है कि कैसे "सफाई" प्रक्रिया के बाद, "सीवेज को संसाधित" किया जाता है, जिसके परिणामस्वरूप "बायोगैस संयंत्र में उपयोग", "खाद के रूप में घोल का उपयोग", और "सुरक्षित पानी" जैसे उत्पाद बनते हैं। यह अपशिष्ट जल उपचार के विभिन्न चरणों और उसके उपयोग को दर्शाता है।

Answer:

		Cleaning
		\( \downarrow \)
Use in Biogas plant	\( \leftarrow \)	Sewage after processing	\( \rightarrow \)	Use of slurry as fertilizer
		\( \downarrow \)
		Safe Water

In simple words: The conceptual picture illustrates sewage processing where 'Cleaning' leads to 'Sewage after processing', which then yields 'Use in Biogas plant', 'Use of slurry as fertilizer', and 'Safe Water'.

🎯 Exam Tip: When completing conceptual diagrams, identify the core process and its inputs/outputs clearly to fill in the missing steps logically.

 

Question 5. Give scientific reasons. a. Use of mutant strains has been increased in industrial microbiology.
Answer:• By using industrial microbiology, the commercial use of microbes is done. • In such experiments, various economic, social and environment related processes and products are included. • In this, fermentation processes are used to make bread, cheese, wines, enzymes, nutrients, etc. • Different types of antibiotics are also made by using processes of industrial microbiology. • In pollution control and solid waste management, the industrial microbiology becomes helpful. • In farming too biotechnology is used to produce BT crops.
In simple words: Mutant strains are increasingly used in industrial microbiology to enhance the production of various commercial products like enzymes, antibiotics, and biofuels, optimizing efficiency and yield in fermentation and other biotechnological processes.

🎯 Exam Tip: Emphasize that mutant strains are selected for their enhanced ability to produce specific substances or perform processes more efficiently in industrial applications.

 

b. Enzymes obtained by microbial process are mixed with detergents.
Answer:• When detergents are mixed with microbial enzymes, they start working more efficiently. • The cleaning process takes place at lesser temperatures. • Therefore, for better results, enzymes obtained by microbial process are mixed with detergents.
In simple words: Microbial enzymes are added to detergents to improve cleaning efficiency, allowing them to work effectively at lower temperatures and deliver better overall results.

🎯 Exam Tip: The key reason is improved efficiency and ability to clean at lower temperatures, leading to better results and energy saving.

 

c. Microbial enzymes are used instead of chemical catalysts in chemical industry. (OR) Microbial enzymes are said to be eco-friendly.
Answer:• Microbial enzymes are active at low temperature, pH and pressure. • Due to this property, the energy is saved. The costlier erosion-proof instruments need not be used. • In enzymatic reactions, the unnecessary byproducts are not formed as the reactions are highly specific. • The expenses on purification of the product are minimized as no unnecessary products are formed. • The elimination and decomposition of waste material is avoided and enzymes can be reused again. Hence, microbial enzymes which are eco-friendly are used in chemical industry.
In simple words: Microbial enzymes are preferred over chemical catalysts in industry because they are eco-friendly, highly specific, function under mild conditions (low temperature, pH, pressure), save energy, reduce byproduct formation, and simplify product purification.

🎯 Exam Tip: Focus on the eco-friendly aspects: energy saving (mild conditions), high specificity (less waste), and reusability, which make microbial enzymes superior to chemical catalysts.

 

Question 6. Complete the following conceptual picture with respect to its uses.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक वैचारिक चित्र है जो "ज़ैंथन गम" के विभिन्न उपयोगों को दर्शाता है। केंद्रीय बिंदु "ज़ैंथन गम" है, और उसके चारों ओर के बक्से इसके अनुप्रयोगों को सूचीबद्ध करते हैं, जैसे कि टूथपेस्ट, उच्च गुणवत्ता वाले कागज, पिगमेंट, कपड़ा पिगमेंट, उर्वरक और शाकनाशी का उत्पादन। यह खाद्य उद्योग से लेकर कृषि तक, कई क्षेत्रों में ज़ैंथन गम के बहुमुखी उपयोग को उजागर करता है।

Answer:

Tooth paste			Pigments
\( \uparrow \)			\( \uparrow \)
High quality paper	\( \leftarrow \)	Xanthan gum	\( \rightarrow \)	Fertilizers
\( \uparrow \)			\( \uparrow \)
Textile Pigments			Weedicides

In simple words: Xanthan gum is a versatile microbial product used in various industries for applications such as thickeners in toothpaste, quality improver in paper, stabilizer in pigments, and as a component in fertilizers and weedicides.

🎯 Exam Tip: For conceptual maps, identify and list all associated uses or products directly linked to the central concept.

 

Question 7. Complete the following conceptual picture related to environmental management.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक वैचारिक चित्र है जो पर्यावरण प्रबंधन में रोगाणुओं की भूमिका को दर्शाता है। केंद्रीय बिंदु "माइक्रोब्स" है। यह दिखाता है कि माइक्रोब्स को "तेल रिसाव" (Oil spill) को साफ करने के लिए इस्तेमाल किया जा सकता है और उनके अन्य उपयोगों में "माइक्रोबियल इनोक्यूलेंट", "बायोफ्यूल्स", "बायोपेस्टिसाइड्स", "बायोगैस और खाद", "सीवेज उपचार" और "लैंडफिलिंग" शामिल हैं। यह पर्यावरण संबंधी विभिन्न समस्याओं को हल करने में सूक्ष्मजीवों के व्यापक अनुप्रयोग को दर्शाता है।

Answer:

	Oil spill
Microbial Inoculants	\( \leftarrow \)	Microbes	\( \rightarrow \)	Biofuels
Biopesticides	\( \leftarrow \)		\( \rightarrow \)	Sewage Treatment
	Biogas and composting	\( \leftarrow \)	Land filling

In simple words: Microbes play a critical role in environmental management, cleaning up oil spills, and contributing to the production of biofuels, biopesticides, microbial inoculants, biogas, compost, and efficient sewage treatment through processes like land-filling.

🎯 Exam Tip: Remember specific examples of microbial applications in environmental management, such as oil spill remediation and waste treatment, to accurately complete the diagram.

 

Question 8. Answer the following questions. a. What is the role of microbes in compost production?
Answer:• Microbes can bring about natural decomposition of the organic compounds. • During the biodegradation, some bacteria andmfungi bring about such decomposition and release the inorganic constituents back into the nature. • Compost is formed in such a way by recycling process.
In simple words: Microbes facilitate compost production by naturally decomposing organic materials through biodegradation, releasing inorganic constituents and nutrients back into the soil as part of a recycling process.

🎯 Exam Tip: Focus on the decomposition and nutrient cycling roles of microbes in turning organic waste into valuable compost.

 

b. What are the benefits of mixing ethanol with petrol and diesel?
Answer: When only diesel or petrol is used as fuel, there is increased air pollution. Morevoer, since these are non-renewable and exhaustible fuels, they will be finished in next some years. When petrol and diesel is mixed with ethanol, the proportion of CO2, CO, and hydrocarbons which are emitted in the atmosphere becomes lesser. The particulate pollutants which otherwise are emitted through combustion of petrol and diesel are not formed when fuels are mixed with ethanol. By adding ethanol to the fuels, the cost of expensive petrol or diesel also becomes less. The ethanol burns more efficiently hence ethanol is mixed with petrol and diesel.
In simple words: Mixing ethanol with petrol and diesel reduces air pollution by decreasing CO2, CO, and hydrocarbon emissions, eliminates particulate pollutants, lowers fuel costs, and improves combustion efficiency, making it a more sustainable option.

🎯 Exam Tip: Highlight both the environmental advantages (reduced emissions, cleaner burning) and economic benefits (lower cost, improved efficiency) of ethanol-blended fuels.

 

c. Which plants are cultivated to obtain the fuel?
Answer:• The ethanol is obtained from wheat, maize, beet, sugarcane and molasses of sugarcane. • For biodiesel, the soybean, rapeseed, jatropa, mahua, flaxseed, mustard, sunflower, palm, jute and some types of algae are cultivated.
In simple words: Plants like wheat, maize, beet, and sugarcane are cultivated for ethanol production, while soybean, rapeseed, Jatropha, and sunflower are used to obtain biodiesel.

🎯 Exam Tip: Be able to name specific plant sources for both ethanol (e.g., sugarcane) and biodiesel (e.g., soybean).

 

d. Which fuels are obtained from biomass?
Answer: From biomass, the biogas and biodiesel are mainly obtained. The biogas is obtained from dung of cattle. The fermentation of cattle dung gives rise to methane. From methane, methanol is obtained. Ethanol is obtained from molasses of sugarcane and some other crops. In some countries, special crops are cultivated for the biodiesel.
In simple words: Biogas (from cattle dung fermentation) and biodiesel (from specialized crops like soybean or Jatropha) are the primary fuels obtained from biomass, alongside ethanol derived from sugarcane molasses and other crops.

🎯 Exam Tip: Differentiate between the types of fuels (biogas, biodiesel, ethanol) and their respective biomass sources (dung, oilseeds, sugarcane).

 

e. How does the bread become spongy?
Answer:• When the dough for bread is prepared, the baker's yeast - Saccharomyces cerevisiae is added to it. • This yeast carries out anaerobic fermentation. • This results in formation of CO2 and ethanol. • The CO2 formed tries to escape out of the flour and thus the dough rise. When such dough is baked, it produces spongy bread.
In simple words: Bread becomes spongy because baker's yeast (Saccharomyces cerevisiae) ferments the dough, producing carbon dioxide gas which gets trapped, causing the dough to rise and creating a porous, spongy texture upon baking.

🎯 Exam Tip: Explain the role of yeast in producing CO2 through fermentation, which causes the dough to rise and gives bread its spongy texture.

 

Project: (Do It Your Self)

Project 1. Find the ways to implement the zero garbage system at domestic level.

Project 2. Which are the microbes that destroy the chemical pesticides in soil?

Project 3. Collect more information about reasons for avoiding the use of chemical pesticides.

Can You Recall?

Question 1. Which different microbes are useful to us?
Answer: Many microbes are useful to us, such as bacteria which are used for making curds from milk, yeast used to ferment the batter of bread, bacteria used for making other milk products, bacteria and fungi used for making antibiotics. The bacteria are even used for pollution control.
In simple words: Microbes are useful for producing food items like curds and bread, manufacturing antibiotics, creating other milk products, and even for pollution control.

🎯 Exam Tip: Provide diverse examples of microbial utility, covering food, medicine, and environmental applications.

 

Question 2. Which different products can he produced with the help of Microbes?
Answer: Milk products, cheese, cocoa, pickles made from vegetables, wine and other beverages, bread, probiotic substances and cattle feed are produced with the help of microbes.
In simple words: Microbes help produce a wide range of products including dairy items like milk products and cheese, fermented foods such as pickles and bread, beverages like wine, and health supplements like probiotics, as well as cattle feed.

🎯 Exam Tip: List a variety of products, from food and beverages to health supplements, to demonstrate the broad impact of microbes in production.

 

Use Your Brain Power.

Question 1. In the earlier class, you had prepared the solution of dry yeast for observation of yeast. Which substance is prepared by its use on commercial basis?
Answer: The commercial production of bread and other bakery products need yeast. In wine and beer making also solution of yeast is required.
In simple words: On a commercial basis, yeast is primarily used for producing bread and other bakery products through fermentation, and is also essential for making wine and beer.

🎯 Exam Tip: Remember that yeast's main commercial applications are in baking (bread) and brewing (wine, beer).

 

Use Your Brain Power.

Question 1. Food materials like cold drinks, ice creams, cakes, juices are available in various colours and flavours. Whether these colours and flavours are really derived from fruits?
Answer: The eatables can be made directly from fruits or essence of fruits. But most of the food products purchased from markets use these colours and flavours which are derived from synthetic chemicals.
In simple words: While some food items may use natural fruit extracts, most commercially available products like cold drinks, ice creams, and cakes utilize synthetic chemicals to achieve their vibrant colors and flavors.

🎯 Exam Tip: Distinguish between natural fruit-derived colors/flavors and the more common synthetic additives used in processed foods.

 

Let's Think:

Question 1. Why is it asked to segregate wet and dry waste in each home?
Answer: The wet waste decomposes on its own as most of the matter therein is biodegradable. This waste can be converted into manure by composting. The dry waste can be picked up by the bhangarwala or kabadiwala. This waste can be reused or recycled. Therefore, if dry and wet wastes are kept separately, the solid waste management becomes much easier. On the contrary if everything is dumped indiscriminately, it adds to the total volume of the solid wastes. This becomes unmanageable. Therefore, to reduce the problems of solid waste management, the dry and wet waste segregation must be done at every point source. This also could fetch wealth from waste.
In simple words: Segregating wet and dry waste at home simplifies solid waste management; wet waste can be composted into manure, while dry waste can be reused or recycled, preventing indiscriminate dumping that makes waste unmanageable.

🎯 Exam Tip: Emphasize that segregation streamlines decomposition for wet waste and facilitates recycling/reuse for dry waste, making waste management more efficient.

 

Question 2. What is done with the segregated waste?
Answer: In big cities, there is a mechanism to pick up the solid waste every day or even twice a day at some places. The segregated garbage is taken by the municipal garbage trucks at the land filling sites. Here it is buried deep in the ground. The dry waste that can be reused or recycled, is sold to the recycling units.
In simple words: Segregated waste is collected and transported to landfill sites for burial, while recyclable dry waste is sent to specialized recycling units for reprocessing.

🎯 Exam Tip: Describe the two main fates of segregated waste: landfill for organic/non-recyclable, and recycling for dry/reusable materials.

 

Question 3. Which is most appropriate method of disposal of dry waste?
Answer: Reuse and recycle is the most appropriate method of disposal of dry waste.
In simple words: The most appropriate method for dry waste disposal is to reuse and recycle materials, minimizing waste sent to landfills.

🎯 Exam Tip: Prioritize "reuse" and "recycle" as the best practices for dry waste management.

 

Choose the correct alternative and write its alphabet against the sub-question number:

Question 1. Enzyme - obtained from fungi is used to produce vegetarian cheese.
(a) lipase
(b) protease
(c) amylase
(d) trypsin
Answer: (b) protease
In simple words: Protease, an enzyme derived from fungi, is used in vegetarian cheese production to coagulate milk proteins.

🎯 Exam Tip: Remember that protease is the enzyme commonly used as a rennet substitute in vegetarian cheese making.

 

Question 2. Milk is subjected to - at the beginning to destroy unwanted microbes.
(a) pasteurization
(b) fermentation
(c) coagulation
(d) decomposition
Answer: (a) pasteurization
In simple words: Pasteurization is the initial heat treatment applied to milk to eliminate harmful microbes and ensure its safety.

🎯 Exam Tip: Pasteurization is a critical initial step in milk processing to ensure safety by destroying pathogens.

 

Question 3. - like compounds are formed due to lactobacilli that gives characteristic taste to the yoghurt.
(a) Lactose
(b) Caesin
(c) Acetyldehyde
(d) All the above
Answer: (c) Acetyldehyde
In simple words: Acetylaldehyde is a key compound produced by lactobacilli, which imparts the distinctive taste to yogurt.

🎯 Exam Tip: Link acetaldehyde directly to the characteristic flavor profile of yogurt, a result of lactobacilli activity.

 

Question 4. Methane can be obtained by - decomposition of urban agricultural and industrial waste.
(a) aerobic
(b) anaerobic
(c) microbial anaerobic
(d) chemical
Answer: (c) microbial anaerobic
In simple words: Methane is produced through microbial anaerobic decomposition of organic waste, a process vital in biogas production.

🎯 Exam Tip: The crucial terms here are "microbial" and "anaerobic" as they precisely describe the biological process of methane generation from waste.

 

Question 6............. are mixed with waste materials at land-filling sites for quicker decomposition.
(a) Microbes
(b) Bioreactors
(c) Fungi
(d) Worms
Answer: (b) Bioreactors
In simple words: Bioreactors containing specific mixtures of bacteria are added to waste materials in landfills to accelerate their decomposition process.

🎯 Exam Tip: Understanding the role of specific microbial applications in waste management is crucial for higher scores.

 

Question 7............. bacteria decompose the xenobiotic chemicals present in sewage.
(a) Hydrocarbonoclastic
(b) Decomposing
(c) E.coli
(d) Phenol oxidizing
Answer: (d) Phenol oxidizing
In simple words: Phenol oxidizing bacteria are specialized microbes that break down xenobiotic, or foreign, chemical compounds found in sewage.

🎯 Exam Tip: Identifying the correct bacterial type for specific decomposition tasks demonstrates detailed knowledge of microbiology applications.

 

Question 8.Microbes are used for ............ of environment polluted due to sewage.
(a) protection
(b) conservation.
(c) bioremediaiion
(d) decomposition
Answer: (c) bioremediaiion
In simple words: Microbes are utilized for bioremediation, which is the process of using biological agents to remove or neutralize pollutants from a contaminated environment like sewage.

🎯 Exam Tip: Correctly using scientific terms like 'bioremediation' in the context of microbial pollution control is key for accuracy.

 

Question 9............. is a powerful antibiotic against tuberculosis.
(a) Streptomycin
(b) Tetracycline
(c) Rifamycin
(d) Bacitracin
Answer: (c) Rifamycin
In simple words: Rifamycin is a potent antibiotic commonly used in the treatment of tuberculosis due to its effectiveness against the causative bacteria.

🎯 Exam Tip: Knowledge of specific antibiotics and their targeted diseases is important for questions on medical microbiology.

 

Question 10.Bacteria are used to clear the oil spills are called .............. bacteria.
(a) phenol oxidizing
(b) electrolytic
(c) hydrocarbonoclastic
(d) decomposing
Answer: (c) hydrocarbonoclastic
In simple words: Hydrocarbonoclastic bacteria are a type of microbes specifically used to break down hydrocarbons, making them effective for cleaning up oil spills.

🎯 Exam Tip: Remembering the names of bacteria with specialized functions in environmental clean-up is a high-scoring detail.

 

Question 11............. convert these salts of uranium into insoluble salts.
(a) Saccharomyces
(b) Thiobacillus
(c) Acidobacillus
(d) Geobacter
Answer: (d) Geobacter
In simple words: Geobacter are microbes known for their ability to convert soluble uranium salts into insoluble forms, which can help in environmental remediation.

🎯 Exam Tip: Specific examples of microbial bioremediation are often tested, so know the microbe-function pairs.

 

Question 12............. a byproduct of fermentation is a biopesticide.
(a) Fluoroacetamide
(b) Vanillin
(c) Aspertame
(d) Spinosad
Answer: (d) Spinosad
In simple words: Spinosad is a natural substance derived from the fermentation of a bacterium, used as an effective biopesticide in agriculture.

🎯 Exam Tip: Understanding fermentation byproducts and their practical applications, like biopesticides, is essential.

 

Question 13............. beverage is obtained by fermentation of apple juice.
(a) Cider
(b) Wine
(c) Coffee
(d) Cocoa
Answer: (a) Cider
In simple words: Cider is an alcoholic beverage produced through the fermentation of apple juice, a common application of microbial processes.

🎯 Exam Tip: Linking specific fruits to their fermented beverage products demonstrates practical knowledge of microbiology.

 

Question 14.Vinegar is the chemically ............. acid.
(a) Citric
(b) Gluconic
(c) Glutamic
(d) Acetic
Answer: (d) Acetic
In simple words: Vinegar is an aqueous solution containing acetic acid, which is produced through the fermentation of ethanol by acetic acid bacteria.

🎯 Exam Tip: Knowing the chemical composition of common food products derived from microbial processes is a fundamental concept.

 

Question 15.In which of the following industries microbial enzymes are not used?
(a) Glass industry
(b) Cheese industry
(c) Tanning industry
(d) Paper industry
Answer: (a) Glass industry
In simple words: Microbial enzymes are widely used in various industries like food processing (cheese), leather (tanning), and pulp (paper), but not typically in the glass manufacturing industry.

🎯 Exam Tip: Differentiate between industries where microbial enzymes play a role and those where they do not, based on their chemical processes.

 

Question 16.Citric acid used in production of beverages, toffees, chocolates is obtained by fermentation of ........ by Aspergillus niger.
(a) grapes
(b) sugar molasses
(c) apple
(d) coffee nuts
Answer: (b) sugar molasses
In simple words: Citric acid, used as a flavor enhancer and preservative, is commercially produced through the fermentation of sugar molasses by the fungus Aspergillus niger.

🎯 Exam Tip: Connect specific microbial organisms and their raw materials to the industrial production of organic acids like citric acid.

Match the pairs:

 

Question 1.

Column 'A'	Column 'B'
(1) Vinegar	(a) Polylactic acid
(2) Xanthan gum	(b) Molasses
	(c) Icecreams and puddings
	(d) Acetic acid

Answer:
(1) Vinegar - Acetic acid
(2) Xanthan gum - Icecreams and puddings
In simple words: Vinegar is chemically acetic acid, while xanthan gum is a thickening agent used in products like ice creams and puddings.

🎯 Exam Tip: Accurately matching products with their chemical compositions or common uses is crucial in these types of questions.

Find the odd one out:

 

Question 1.Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, Streptococcus thermophilus
Answer: Streptococcus thermophilus. (All others are bacteria producing probiotics.)
In simple words: While Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium bifidum are all probiotic bacteria, Streptococcus thermophilus is primarily used in yogurt production, making it the odd one out in terms of general probiotic classification.

🎯 Exam Tip: Differentiating between microorganisms based on their primary roles (e.g., probiotics vs. fermentation starters) helps in "odd one out" questions.

 

Question 2.Lactobacillus lactis, Bifidobacterium bifidtim, Lactobacillus cremoris, Streptococcus thermophilus
Answer: Bifidobacterium bifidum. (All others are bacteria used in cheese production.)
In simple words: Lactobacillus lactis, Lactobacillus cremoris, and Streptococcus thermophilus are commonly used in cheese production, whereas Bifidobacterium bifidum is primarily a probiotic bacterium.

🎯 Exam Tip: Grouping bacteria by their specific industrial applications, such as cheese making or probiotic supplements, is a key skill.

 

Question 3.Dark chocolate, Miso soup, Wafers, Corn syrup
Answer: Wafers. (All others are probiotic products.)
In simple words: Dark chocolate, miso soup, and corn syrup can be produced or contain ingredients from microbial fermentation, often with probiotic benefits, while wafers are generally a baked good without such a direct microbial connection.

🎯 Exam Tip: Identify products that involve fermentation or contain probiotics as opposed to those that are processed differently.

 

Question 4.Vinegar, Soya sauce, Ketchup, Monosodium glutamate
Answer: Ketchup. (All others are products prepared by microbial fermentation.)
In simple words: Vinegar, soya sauce, and monosodium glutamate (MSG) are all products derived from microbial fermentation, whereas ketchup is typically made from tomatoes and spices, not directly via fermentation.

🎯 Exam Tip: Focus on the primary production method – fermentation – to distinguish the odd one out in a list of food products.

 

Question 5.Actinomycetes, Streptomyces, Nocardia, yeast
Answer: Yeast. (All others have ability of decomposing rubber from garbage.)
In simple words: Actinomycetes, Streptomyces, and Nocardia are all types of bacteria known for their ability to decompose various complex organic materials, including rubber, while yeast is a fungus primarily known for fermentation.

🎯 Exam Tip: Classify microorganisms by their general type (bacteria vs. fungi) and primary metabolic roles to correctly identify the outlier.

Find the correlation:

 

Question 1.Bread Baker's yeast :: Soya sauce : ............
Answer: Bread Baker's yeast : : Soya sauce : Aspergillus oryzae
In simple words: Just as baker's yeast is used to ferment bread, Aspergillus oryzae is the microorganism used in the fermentation process for making soya sauce.

🎯 Exam Tip: This question tests your knowledge of specific microbes paired with the food products they help create through fermentation.

 

Question 2.Coffee: Caffea arabica :: Cocoa: ............
Answer: Coffee: Coffea arabica :: Cocoa: Theobroma cacao
In simple words: The correlation links coffee to its plant species, Coffea arabica; similarly, cocoa is derived from the Theobroma cacao plant.

🎯 Exam Tip: Understanding the botanical origins of common beverages and food products is important for these correlation questions.

 

Question 3.Oil slick : Alcanovorax : Rubber from garbage : ............
Answer: Oil slick : Alcanovorax : Rubber from garbage : Actinomycetes
In simple words: Alcanovorax bacteria are used to break down oil slicks, and similarly, Actinomycetes are known for their ability to decompose rubber found in garbage.

🎯 Exam Tip: Remember specific microorganisms and their role in decomposing different types of environmental pollutants for this correlation.

 

Question 4.Conversion of metals into comounds: Thiobacilli :: Conversion of uranium salts : ............
Answer: Conversion of metals into comounds : Thiobacilli : : Conversion of uranium salts : Geobacter.
In simple words: Thiobacilli are involved in the conversion of metals, and likewise, Geobacter are known for their role in converting uranium salts into insoluble forms for bioremediation.

🎯 Exam Tip: This question assesses your knowledge of specific bacteria involved in the bioconversion of different elements or compounds.

Name the following:

 

Question 1.Microbial enzymes.
Answer: Oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases.
In simple words: Microbial enzymes are biological catalysts, broadly classified into types like oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases, each performing specific biochemical reactions.

🎯 Exam Tip: Listing the main classes of enzymes demonstrates a fundamental understanding of enzymology in microbiology.

 

Question 2.Emulsifiers.
Answer: Polysaccharides and glycolipids.
In simple words: Emulsifiers are substances that help mix two immiscible liquids, and examples from microbial sources include certain polysaccharides and glycolipids.

🎯 Exam Tip: Knowing examples of microbial products, such as emulsifiers like polysaccharides and glycolipids, is important for industrial microbiology applications.

 

Question 3.Microbe used in preparation of wine and cider.
Answer: Saccharomyces cerevisiae.
In simple words: Saccharomyces cerevisiae, commonly known as brewer's or baker's yeast, is the primary microbe responsible for the alcoholic fermentation required to produce wine and cider.

🎯 Exam Tip: The name Saccharomyces cerevisiae is a common answer for questions related to fermentation in beverage production.

 

Question 4.Effective antibiotic against tuberculosis.
Answer: Rifamycin.
In simple words: Rifamycin is a potent antibiotic specifically recognized for its effectiveness in treating tuberculosis.

🎯 Exam Tip: Direct recall of key antibiotics for major diseases like tuberculosis is a frequent examination point.

 

Question 5.Antibiotics.
Answer: Penicillin, cephalosporins, monobactam, erythromycin, gentamycin, neomycin, streptomycin, tetracyclins, vancomycin.
In simple words: Antibiotics are medicines that fight bacterial infections, and common examples include penicillin, cephalosporins, erythromycin, and tetracyclines.

🎯 Exam Tip: Be able to list several common antibiotics, demonstrating a broad understanding of antimicrobial agents.

 

Question 6.Bacteria that use sulphuric acid as source of energy.
Answer: Acidobacillus ferroxidens, Acidophillium spp.
In simple words: Acidobacillus ferroxidens and Acidophillium species are bacteria capable of utilizing sulphuric acid as an energy source, which is beneficial in controlling soil pollution from acid rain.

🎯 Exam Tip: Knowing specific acid-tolerant bacteria and their energy sources highlights specialized microbial adaptations.

 

Question 7.Substance that makes biodegradable plastic.
Answer: Polylactic acid.
In simple words: Polylactic acid (PLA) is a common bioplastic material derived from renewable resources, making it biodegradable.

🎯 Exam Tip: Identify common biodegradable materials and their primary components, especially in the context of environmental solutions.

 

Question 8.Curd like food product made from sheep milk.
Answer: Kefir.
In simple words: Kefir is a fermented milk product, similar to yogurt, traditionally made using kefir grains which ferment various milks, including sheep's milk.

🎯 Exam Tip: Familiarity with diverse fermented dairy products and their source animals or origins is helpful.

 

Question 9.Enzyme used to make vegetarian cheese.
Answer: Protease.
In simple words: Protease enzymes are used in vegetarian cheese production to coagulate milk proteins, offering an alternative to animal-derived rennet.

🎯 Exam Tip: Understand the role of enzymes in food processing, particularly the alternatives used for vegetarian products.

 

Question 10.Fungus used for making soya sauce.
Answer: Aspergillus oryzae.
In simple words: Aspergillus oryzae is a crucial fungus used in the initial fermentation stage of making soya sauce, breaking down proteins and starches.

🎯 Exam Tip: Connect specific fungi to their roles in traditional food fermentations like soya sauce production.

Complete the charts:

 

Question 1.

Fruit	Microbe used	Name of beverage
Caffea arabica		Coffee
Theobroma cacao	Candida, Hansenula, Pichia, Saccharomyces
Grapes		Wine
Apple	Saccharomyces cerevisiae

Answer:

Fruit	Microbe used	Name of beverage
Caffea arabica	Lactobacillus brevis	Coffee
Theobroma cacao	Candida, Hansenula, Pichia, Saccharomyces	Cocoa
Grapes	Saccharomyces cerevisiae	Wine
Apple	Saccharomyces cerevisiae	Cider

In simple words: This chart illustrates the specific microbial involvement in the production of various fruit-based beverages, highlighting the fermentation agents.

🎯 Exam Tip: Memorizing the correct microbe-fruit-beverage combinations is key for accurately completing such charts.

 

Question 2.

Source	Microbe	Amino acid	Use
Sugar and beet molasses, ammonia salt			Production of monosodium glutamate (Ajinomoto).
	Aspergillus niger		Drinks, toffees, chocolate production.
Glucose, corn steep liquor		Gluconic acid
Molasses, corn steep liquor	Lactobacillus delbrueckii
	Aspergillus itaconius	Itaconic acid

Answer:

Source	Microbe	Amino acid	Use
Sugar and beet molasses, ammonia salt	Brevibacterium, Corynobacterium	L-glutamic acid	Production of monosodium glutamate (Ajinomoto).
Sugar molasses, salt	Aspergillus niger	Citric acid	Drinks, toffees, chocolate production.
Glucose, corn steep liquor	Aspergillus niger	Gluconic acid	Production of minerals used as supplement for calcium and iron.
Molasses, corn steep liquor	Lactobacillus delbrueckii	Lactic acid	Source of nitrogen, production of vitamins.
Molasses, corn steep liquor	Aspergillus itaconius	Itaconic acid	Paper, textile, plastic industry, gum production

In simple words: This table summarizes the industrial production of various amino acids and other chemicals, showing the specific raw materials, microbes, and their ultimate uses.

🎯 Exam Tip: Mastering these industrial microbiology charts requires knowing the input (source), the microbial agent, the product, and its application.

 

Question 3.

Source	Microbe	Amino acid
(1) Sugar molasses and salt		Citric acid
(2)	Lactobacillus delbrueckii
(3) Corn steep liquor	Aspergillus itaconius

Answer:

Source	Microbe	Amino acid
(1) Sugar molasses and salt	Aspergillus niger	Citric acid
(2) Molasses, corn steep liquor	Lactobacillus delbrueckii	Lactic acid
(3) Corn steep liquor	Aspergillus itaconius	Itaconic acid

In simple words: This chart identifies the specific microbes that ferment different sources (sugar molasses, corn steep liquor) to produce important organic acids like citric, lactic, and itaconic acid.

🎯 Exam Tip: Pay close attention to the specific microbe and the resulting amino acid for each source material to correctly complete this table.

Answer the following questions:

 

Question 1.Which microbes are used in the baking industries?
Answer: Yeast i.e. Saccharomyces cerevisiae is used in the baking industries.
In simple words: Saccharomyces cerevisiae, commonly known as baker's yeast, is the primary microbe used in baking to leaven dough through fermentation.

🎯 Exam Tip: The name of baker's yeast is fundamental for questions on fermentation in the food industry.

 

Question 2.There is an oil layer on the water surface of river in your area. What will you do?
Answer: If there is an oil layer on the water surface, we shall use hydrocarbonoclastic bacteria like Pseudomonas to clean up the oil spill.
In simple words: To clean an oil layer on a river surface, we would introduce hydrocarbonoclastic bacteria such as Pseudomonas, which can break down the oil.

🎯 Exam Tip: Providing a practical solution using specific microbial agents for environmental pollution demonstrates application-based knowledge.

 

Question 3.(a) How are microbes used in sewage management?
(b) How is the sludge produced in this process utilized?
Answer:
(a)
• In cities, the sewage is sent to processing plant and is treated with microbes.
• Microbes that carry out decomposition, are mixed with sewage. Such microbes are able to destroy, pathogens as well as decompose any compounds.
• Some microbes bring about bioremediation of environment, that are used for treating sewage pollution.
• Upon decomposition of the carbon compounds present in sewage, microbes release methane and CO2.
In simple words: Microbes are crucial in sewage management as they decompose organic compounds and pathogens, releasing gases like methane and CO2, and thus purifying the wastewater.

🎯 Exam Tip: Clearly outlining the steps and benefits of microbial action in sewage treatment, including gas production, is important.

 

(b) The sludge formed in this process, is used as fertilizer.
In simple words: The solid waste, or sludge, generated during microbial sewage treatment is rich in nutrients and can be safely used as fertilizer after further processing.

🎯 Exam Tip: Remember the valuable byproduct of sewage treatment, which is sludge used as a bio-fertilizer.

 

Question 4.(a) What is clean technology?
Answer: Clean technology is the method to use microbes for controlling air, soil and water pollution. These microbes can degrade the manmade chemicals.
In simple words: Clean technology refers to using microorganisms to break down pollutants in air, soil, and water, thereby reducing environmental contamination.

🎯 Exam Tip: Define 'clean technology' by highlighting the role of microbes in degrading pollutants across different environmental mediums.

 

(b) Why is it essential to ban plastic bags?
Answer: Plastic is a non-biodegradable substance. It cannot be degraded back into its original constituents. It remains just like that for many hundreds of years. It causes solid waste pollution in any environment wherever it is thrown indiscriminately. If burnt, it releases very toxic gases. If dumped in landfills it obstructs the other decomposition processes.
If thrown in water bodies, it causes harm to aquatic life. Cattle graze on plastic unknowingly and are killed by it as it clogs inside their alimentary canal. The gutters and rain water drains get clogged due to plastic bags and this causes cities to submerge in water during heavy rains. Nowadays, the fishermen get more than half of plastic if they cast their net in the sea.
People use the plastic bags indiscriminately without any thought towards their environmental impact. There are better alternatives for plastic bags such as cloth bags which can be reused again and again. Therefore, it is absolutely necessary to ban the use of plastic bag.
In simple words: Banning plastic bags is essential because they are non-biodegradable, cause widespread pollution, harm wildlife, clog drainage systems, and release toxic gases if burned, posing severe environmental and health risks.

🎯 Exam Tip: When explaining environmental issues, provide multiple impacts (pollution, wildlife, infrastructure) to demonstrate comprehensive understanding.

Write short notes on the following:

 

Question 1.Production of Yoghurt.
Answer:
• Yoghurt is one of the milk product produced from milk with the help of lactobacilli (inoculant).
• In the industrial production of yoghurt, the milk is added with condensed milk powder. This increases the protein content of the milk. Then this milk is subjected to fermentation.
• Milk is boiled and then it is cooled till it becomes lukewarm.
• Then the bacterial strains of Streptococcus thermophiles and Lactobacillus delbrueckii are added to this lukewarm milk in 1:1 proportion.
• The Streptococcus bacteria convert the milk into solution containing lactic acid. This makes the proteins to gel out. It makes the yoghurt dense.
• The lactobacilli help in the formation of acetaldehyde like compounds giving a characteristic taste to the yoghurt.
• For commercial reasons, various fruit juices are mixed with yoghurt to impart different flavours forming strawberry yoghurt, banana yoghurt, etc.
• The pasteurization is carried out to increase the shelf life of yoghurt and improve its probiotic properties.
In simple words: Yoghurt production involves fermenting milk with specific bacteria like Streptococcus thermophilus and Lactobacillus delbrueckii, which convert lactose to lactic acid, coagulating milk proteins and developing its characteristic taste and texture, often enhanced with flavors and pasteurization for shelf life.

🎯 Exam Tip: Detail the specific bacterial strains, the chemical changes (lactic acid production, protein coagulation), and commercial aspects (flavoring, pasteurization) for a complete answer.

 

Question 2.Production of cheese.
Answer: Cheese is made from cow's milk throughout the world. The steps in the process of cheese manufacture are as follows:
• Chemical and microbiological testing of milk is done.
• Three types of bacteria, viz. Lactobacillus lactis, Lactobacillus cremoris and Streptococcus thermophilus along with some colour is added to the milk.
• It imparts sourness to the milk and it is converted into yoghurt like substance.
• The water from this yoghurt, i.e. whey is not removed to make the yoghurt denser.
• Enzyme, rennet or protease is added to the mixture to make it more denser.
• Later cutting the solid yoghurt into pieces, washing, rubbing, salting, land mixing of essential microbes, pigments and flavours is done in suitable steps.
• The pressed cheese is then cut in to pieces and stored for ripening.
In simple words: Cheese production begins with milk testing, followed by adding specific bacteria (Lactobacillus lactis, L. cremoris, S. thermophilus) to acidify and curdle the milk, then rennet or protease is added for further coagulation, and finally, the curd is cut, processed, and ripened.

🎯 Exam Tip: Outline the key stages from milk preparation to ripening, including the role of specific bacteria and enzymes, for a comprehensive explanation.

 

Question 3.Land-filling sites.
Answer:
• In the land-filling sites the degradable wastes are transferred. Usually such sites are in urban areas.
• The land-filling sites are away from the residential areas for the hygienic reasons. Here large pits arb dug in open spaces.
• These pits are lined with plastic sheets. Therefore, the leaching of toxic and harmful materials is avoided to reduce the chance of soil pollution due to leachates.
• Compressed waste is put in the pit and is covered with layers of soil, saw dust, leafy waste.
• Specific biochemical substances are added for speedy decomposition.
• Bioreactors which are mixtures of bacteria are mixed at some places.
• Soil microbes and other top layers decompose the waste.
• Soil slurry is used to seal the pits completely.
• After a certain period, best quality compost is formed. Such land filling sites can be reused after removal of compost.
In simple words: Land-filling sites are designated areas, often outside residential zones, where degradable waste is compacted, layered with soil, and treated with microbes or bioreactors to facilitate decomposition and produce compost, preventing leachate and enabling future reuse.

🎯 Exam Tip: Describe the structure (lined pits), process (compaction, layering, microbial addition), and outcomes (decomposition, compost, leachate prevention) of landfill sites.

 

Question 1.(Nocardia, Geobacter, Ideonella sakaiensis, Pseudomonas, Alcanovorax borkumensis, hydrocarbonoclastic, Acidophillium, streptomyces)
Bacteria like Pseudomonas spp. and Alcanovorax borkumensis have the ability to destroy the pyridines and other chemicals. Hence, these bacteria are used to clear the oil spills. These are called hydrocarbonoclastic bacteria. It has been observed that species like Vibrio, Ideonella sakaiensis can decompose the PET. Similarly, species of fungi like Nocardia have ability of decomposing rubber from garbage. Sulphuric acid is source of energy for some species of bacteria like Acidophillium. Hence, these bacteria can control the soil pollution occurring due to acid rain. Geobacter convert the salts of uranium into insoluble salts.
In simple words: Microbes like Pseudomonas and Alcanovorax borkumensis clear oil spills as hydrocarbonoclastic bacteria, Ideonella sakaiensis decomposes PET, Nocardia fungi break down rubber, Acidophillium bacteria use sulphuric acid to mitigate acid rain pollution, and Geobacter converts uranium salts into insoluble forms for remediation.

🎯 Exam Tip: For paragraph completion, focus on logical connections between the problem (oil spills, PET, rubber, acid rain, uranium salts) and the specific microbial solution mentioned in the given options.

Read the paragraph and answer the questions given below:

Remediation is the process of removing dangerous or poisonous substances from the environment, or limiting the effect that they have on it. When any biological organism is used for remediation, it is called bioremediation. When plant species are used for the purpose of remediation, it is called phytoremediation. When any microbes are used then it is named as microbial remediation. The methods of such remediation have helped to clean the environment from toxic effluents, especially sewage and crude oil. Dr. Anand Chakraborty, a scientist of Indian origin, has worked on Pseudomonas aeruginosa which have reduced the crude oil films into carbon dioxide and water.

Questions and Answers:

 

Question 1.What is the meaning of remediation?
Answer: Remediation is the process by which dangerous or toxic substances are removed from the environment.
In simple words: Remediation means cleaning up or neutralizing harmful substances in the environment.

🎯 Exam Tip: Provide a concise and accurate definition directly from the given passage.

 

Question 2.What is the difference between phytoremediation and microbial remediation?
Answer: When any plant species are used for remediation process, then it is called phytoremediation, whereas when any microbe species used for remediation then it is called microbial remediation.
In simple words: Phytoremediation uses plants to clean up pollutants, while microbial remediation uses microbes for the same purpose.

🎯 Exam Tip: Clearly distinguish between the two terms by focusing on the biological agent used for remediation (plants vs. microbes).

 

Question 3.Which environmental pollutant is mainly removed through bioremediation processes?
Answer: Toxicants released through sewage and crude oil are removed by bioremediation processes.
In simple words: Bioremediation primarily removes toxicants from sewage and crude oil spills.

🎯 Exam Tip: Identify the specific pollutants mentioned in the paragraph that are targeted by bioremediation.

 

Question 1. Observe the diagram and answer the following questions:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक आधुनिक लैंडफिल साइट को दर्शाता है जहाँ कचरा (garbage) को मिट्टी की परत (soil cover) से ढककर संसाधित (processing on sewage) किया जाता है। इसमें मीथेन गैस संग्रह प्रणाली और भूजल स्तर की निगरानी के लिए एक कुआँ भी दिखाया गया है, जो अपशिष्ट प्रबंधन की विधि का चित्रण करता है।
(a) Name the following method of solid waste management.
Answer: The above diagram shows modern landfill site. This method is used for solid waste management.
In simple words: This diagram illustrates a modern landfill, a structured site for disposing of solid waste where materials are buried to manage waste and prevent environmental harm.

🎯 Exam Tip: Clearly identifying the type of waste management method shown in the diagram is crucial for scoring. Focus on key features like 'landfill' and 'waste management'.

 

Question 2. Observe the Figure 7.1 and answer the following questions:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक आधुनिक लैंडफिल साइट को दर्शाता है, जहाँ कचरा (garbage) को मिट्टी से ढका जाता है, मीथेन गैस संग्रह की व्यवस्था है, और सीवेज का प्रसंस्करण (processing on sewage) किया जाता है। एक कुआँ भूजल स्तर की निगरानी के लिए भी दिखाया गया है, जो अपशिष्ट निपटान की एक वैज्ञानिक विधि को प्रदर्शित करता है।
(a) Identify the process shown in the figure.
Answer: The figure shows modern land fill site where microbial biodegradation process is carried out.
In simple words: The image displays a modern landfill designed for solid waste disposal, where microbes naturally break down organic matter through biodegradation.

🎯 Exam Tip: Accurate identification of the process, specifically "microbial biodegradation" within a "landfill site," is key to a complete answer. Mentioning both aspects shows thorough understanding.

 

(b) Explain the process in short.
Answer: Land-filling sites:
• In the land-filling sites the degradable wastes are transferred. Usually such sites are in urban areas.
• The land-filling sites are away from the residential areas for the hygienic reasons. Here large pits arb dug in open spaces.
• These pits are lined with plastic sheets. Therefore, the leaching of toxic and harmful materials is avoided to reduce the chance of soil pollution due to leachates.
• Compressed waste is put in the pit and is covered with layers of soil, saw dust, leafy waste.
• Specific biochemical substances are added for speedy decomposition.
• Bioreactors which are mixtures of bacteria are mixed at some places.
• Soil microbes and other top layers decompose the waste.
• Soil slurry is used to seal the pits completely.
• After a certain period, best quality compost is formed. Such land filling sites can be reused after removal of compost.
In simple words: Modern landfills involve burying degradable waste in lined pits away from residential areas. The waste is compressed, covered with layers of soil and organic matter, and treated with microbes and bioreactors to accelerate decomposition, ultimately producing compost and allowing site reuse.

🎯 Exam Tip: When explaining a process, ensure to cover its key stages, from waste reception and preparation to microbial action and the final outcome. Mentioning environmental safeguards like plastic lining adds value.

Activity Based Questions:

 

Question 1. Collect Information Search : (Textbook page no. 84)

(i) Which materials should not be present in garbage for its proper microbial decomposition?
Answer: If there are non-biodegradable materials in the garbage, they will not decompose. The plastic, glass, metals etc. will not undergo microbial decomposition, therefore, such items should not be- there in the garbage. The toxic matter, hazardous chemicals and e-waste should also be removed. If such materials are present in the garbage, the microbes will be killed and the entire process of decomposition will be suffered.
In simple words: For effective microbial decomposition, garbage should be free of non-biodegradable items like plastic, glass, and metals, as well as toxic chemicals and e-waste, which can hinder the breakdown process and harm beneficial microbes.

🎯 Exam Tip: Listing specific non-biodegradable items (plastic, glass, metals) and harmful substances (toxic chemicals, e-waste) demonstrates a clear understanding of what impedes microbial decomposition.

 

(ii) How the sewage generated in your house or apartment is disposed off ?
Answer: The sewage generated in our house is carried by the drainage pipes to municipal sewage treatment plants. Here, primary, secondary and tertiary treatment is done on the sewage. The safe water is then released into the ocean.
In simple words: Household sewage is transported via drainage systems to municipal treatment plants, where it undergoes primary, secondary, and tertiary treatments before the cleaned water is discharged into the ocean.

🎯 Exam Tip: Focus on the journey of sewage, from household pipes to municipal treatment plants, and the multi-stage treatment process (primary, secondary, tertiary) before final disposal to ensure a comprehensive answer.

 

Question 2. Observe: (Textbook page no. 83)

Observe the garbage vans of gram panchayat and municipality. Nowadays, there is facility of decreasing the volume of garbage by compaction in those vans. Explain the advantages of this activity.
Answer: When the garbage is compressed, its volume is reduced. The trips of the vans that pick up the garbage can be reduced due to such measures. The land filling sites can also accommodate more garbage if it is compacted.
In simple words: Compacting garbage in vans reduces its volume, leading to fewer collection trips and allowing landfills to hold more waste, making waste management more efficient.

🎯 Exam Tip: Highlight the direct benefits of compaction: reduced volume, fewer trips for waste collection, and increased capacity of landfill sites, demonstrating practical understanding.

 

Question 3. Observe the figure and answer the following:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक पाइप से बहते हुए काले गंदे पानी को एक जल निकाय में छोड़ते हुए दिखाता है, जो अपशिष्ट जल प्रबंधन की कमी और प्रदूषण को दर्शाता है। इससे पता चलता है कि अनुपचारित सीवेज सीधे पर्यावरण में छोड़ा जा रहा है, जिससे जल प्रदूषण होता है।
(i) Lack of management of which factor is shown in the picture?
Answer: The above picture shows the lack of management of sewage resulting in waste water being dumped carelessly.
In simple words: The image depicts poor sewage management, where untreated wastewater is carelessly discharged, causing environmental pollution.

🎯 Exam Tip: Clearly state that the picture illustrates "lack of sewage management" and specify the consequence: "waste water being dumped carelessly."

 

(ii) How can that factor be managed with the help of microbes?
Answer: Microbes which can destroy the pathogens of cholera, typhoid, etc. are mixed with sewage. They release methane and CO2 by decomposition of the carbon compounds present in sewage. Other microbes that decompose chemical compounds are also released. Phenol oxidizing bacteria decompose the xenobiotic chemicals present in sewage.
In simple words: Microbes can treat sewage by decomposing carbon compounds, releasing methane and CO2, and destroying pathogens and xenobiotic chemicals like phenols, thereby cleaning the wastewater.

🎯 Exam Tip: When explaining microbial management, mention the specific actions of microbes: destroying pathogens, decomposing carbon compounds (releasing methane/CO2), and breaking down chemical pollutants like xenobiotic chemicals via specialized bacteria.

 

(iii) How are the oil spills in oceans cleared?
Answer: Hydrocarbonoclastic bacteria like Alcanivorax borkumensis and Pseudomonas are used to clear the oil spillage from ocean water. These bacteria decompose the hydrocarbons. They bring about the reaction of released carbon with oxygen to produced CO2 and water.
In simple words: Oil spills in oceans are cleaned using hydrocarbonoclastic bacteria such as Alcanivorax borkumensis and Pseudomonas, which break down hydrocarbons into carbon dioxide and water.

🎯 Exam Tip: Naming specific "hydrocarbonoclastic bacteria" like Alcanivorax borkumensis or Pseudomonas, and explaining their function (decomposing hydrocarbons into CO2 and water), will yield full marks.