Class 12 Biology Case Study Questions Chapter 10 Microbes in Human Welfare

In Class 12 Boards there will be Case studies and Passage Based Questions will be asked, So practice these types of questions. Study Rate is always there to help you. Free PDF Downloads of CBSE Class 12 Biology Chapter 10 Microbes in Human Welfare Case Study and Passage-Based Questions with Answers were Prepared Based on the Latest Exam Pattern. Students can solve NCERT Class 12 Biology Case Study Questions Microbes in Human Welfare to know their preparation level.

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In CBSE Class 12 Biology Paper, There will be a few questions based on case studies and passage-based as well. In that, a paragraph will be given, and then the MCQ questions based on it will be asked.

Microbes in Human Welfare Case Study Questions With Answers

Here, we have provided case-based and passage-based questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Case Study/Passage-Based Questions

Case Study 1:Yeast and certain bacteria play a key role in fermentation to break down carbohydrates into ethanol and carbon dioxide which are then further used to prepare acetic acid with the help of the bacterium Acetobacteraceti. Alcoholic fermentation in anaerobic process, but the conversion of alcohol to acetic acid is aerobic.
This process can be represented by the following equation :

The rate of alcohol production is measured on the basis of
(a) amount of sugar present in the medium
(b) amount of CO2 produced per unit of time
(c) amount of yeast added in the medium
(d) all of these.

Answer: (b) amount of CO2 produced per unit of time


A number of chemicals are produced at the time of alcoholic fermentation with the change of nutrient media, pH and aeration. Select such a by-product from the following.
(a) Butanol (b) Succinic acid
(c) Acetaldehyde (d) All of these

Answer: (d) All of these ​


During alcoholic fermentation of cereals and potato, the crushed food mixed with hot water for obtaining malt is called
(a) juice (b) mash
(c) wort (d) None of these.

Answer: (b) mash ​


Distilled alcohol with 95% ethanol content is called
(a) absolute alcohol (b) rectified spirit
(c) gin (d) brandy

Answer: (b) rectified spirit ​


___________ is used in the preparation of vinegar.
(a) toddy (b) acetic acid
(c) butter (d) both (a) and (b)

Answer: (d) both (a) and (b) ​


Case Study/Passage-Based Questions

Case Study 2: Villagers in a place near Chamber started planning to make a power supply for agricultural purposes from cow dung. They have started a biogas plant for this purpose. Study the flow chart for biogas production given below and answer the following questions.

Biogas is composed of majorly
(a) methane, CO2 and O2
(b) CO2, H2S and H2O
(c) methane, CO2 and H2S
(d) H2S, H and O2.

Answer: (c) methane, CO2 and H2S ​


In the given flow chart, ‘A’ denotes
(a) aerobic bacteria
(b) methanogenic bacteria
(c) cellulose-degrading bacteria
(d) yeast and protozoa

Answer: (b) methanogenic bacteria ​​


What is represented by ‘B’ in the flow chart?
(a) Carbohydrates
(b) Protein polymers
(c) Organic acids
(d) Fat globules

Answer: (c) Organic acids ​​​


‘C’ in the given flow chart causes
(a) aerobic breakdown of complex organic compounds
(b) anaerobic digestion of complex organic compounds
(c) fermentation of organic compounds
(d) fermentation of monomers

Answer: (b) anaerobic digestion of complex organic compounds ​​​​


If ‘A’ is not added in the procedure
(a) methane will not be formed
(b) CO2 will not be formed
(c) organic compounds will not be converted to H2S
(d) O2 will not be formed.

Answer: (a) methane will not be formed ​​​​


Case Study 3: Alcohols are important industrial solvents. Ethanol, methanol, propanol, and butanol are produced commercially by the fermentation activity of some fungi, majorly yeasts. During fermentation, yeast cells convert cereal-derived sugars into ethanol and CO2. At the same time, hundreds of secondary metabolites that influence the aroma and taste of alcohol are produced. Sugar concentration affects the rate of fermentation reactions. Yeast cannot grow in a very strong sugar solution. In the case of complex carbohydrate-containing nutrient media, 1% malt or Rhizopus is used along with yeasts. Hydrolysis of starch is carried out at high temperatures for 30 mins. The crushed food mixed with hot water for obtaining malt is called mash. The nutrient medium prior to fermentation is called wort. Wort is cooled down to the appropriate temperature and inoculated with a strain of yeast.

(i) The rate of alcohol production is measured on the basis of

(a) amount of sugar present in the medium(b) amount of CO2 produced per unit time(c) amount of yeast added in the medium(b) amount of CO2 produced per unit of time

Answer: (b) amount of CO2 produced per unit of time ​​​​


(ii) A number of chemicals are produced at the time of alcoholic fermentation with the change of nutrient media, pH and aeration. Select such by-product from the following.

(a) Phenylethanol(b) Amyl alcohol(c) Glycerol(d) All of these

Answer: (d) All of these ​​​​


(iii) During the alcoholic fermentation of cereals and potatoes, the crushed food mixed with hot water for obtaining malt is called

(a) juice(b) mash(c) wort(d) none of these

Answer: (b) mash ​​​​


(iv) Distilled alcohol with 95% ethanol content is called

(a) absolute alcohol(b) rectified spirit(c) gin(d) brandy.

Answer: (b) rectified spirit ​​​​


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