Are these practice questions for Microbes in Human Welfare based on the CBSE pattern?

Yes. Every practice question is modeled on the CBSE Class 12 - Science Biology exam pattern — including MCQs, assertion-reason questions, and short-answer formats that frequently appear in CBSE papers.

Are the practice questions for Microbes in Human Welfare free?

Yes. Every chapter includes free practice questions for Class 12 - Science students to get you started.

What types of questions are included?

The practice set for Microbes in Human Welfare mainly includes MCQs and CBSE-style short-answer questions, with instant feedback on each answer. For full-length textbook practice, use the NCERT Solutions page.

Are the practice questions suitable for board exam preparation?

Yes. The questions test the same concepts and depth that CBSE asks in board exams. After finishing, also solve the NCERT and NCERT Exemplar exercises for Microbes in Human Welfare for full coverage.

How many practice questions are there for Microbes in Human Welfare?

The number scales with chapter length and concept density. Each chapter typically has 15-50 practice questions across MCQ and short-answer formats.

Microbes in Human Welfare Class 12 Biology Practice Questions with Answers

easy

Evaluate the role of Lactic Acid Bacteria (LAB) in improving the nutritional quality of curd compared to milk.

Try solving it in your notebook first, then check the solution.

easy

Name the bacterium responsible for the large holes in Swiss cheese and the gas it produces.

Try solving it in your notebook first, then check the solution.

easy

Define biofertilisers.

Try solving it in your notebook first, then check the solution.

easy

Examine the specific role of the bacterium Propionibacterium sharmanii in the production of Swiss cheese. What characteristic feature does this microbe impart to the final product?

Try solving it in your notebook first, then check the solution.

easy

Examine the use of microbes in the commercial production of organic acids. Name two different acids, the specific microbe used to produce each, and one industrial application.

Try solving it in your notebook first, then check the solution.

easy

Critique the practice of discharging untreated sewage into rivers, based on its effect on Biochemical Oxygen Demand (BOD).

Try solving it in your notebook first, then check the solution.

easy

Name the group of bacteria responsible for producing biogas and give one common example.

Try solving it in your notebook first, then check the solution.

easy

List three examples of organic acids produced by microbes and name the respective microbe for each.

Try solving it in your notebook first, then check the solution.

easy

Apply your knowledge of microbial metabolism to explain why the dough used for making foods like dosa and idli has a puffed-up appearance after fermentation. Identify the key gas produced and the metabolic process responsible.

Try solving it in your notebook first, then check the solution.

easy

Identify the yeast species used for both bread-making and fermenting beverages.

Try solving it in your notebook first, then check the solution.

medium

Analyze the symbiotic relationship in a mycorrhiza, specifically one formed by a fungus from the genus Glomus. Explain the benefits that both the plant and the fungus derive from this association.

Try solving it in your notebook first, then check the solution.

medium

Describe the role of microbes in a typical biogas plant. Explain the plant's basic structure and the utilization of its products.

Try solving it in your notebook first, then check the solution.

medium

Propose a plan for a small-scale, eco-friendly waste management system for a rural household that integrates biogas production and the use of biofertilisers.

Try solving it in your notebook first, then check the solution.

medium

Propose a reason why

\textit{Baculoviruses}

are considered excellent candidates for integrated pest management (IPM) programs.

Try solving it in your notebook first, then check the solution.

medium

Explain the role of Lactic Acid Bacteria (LAB) in the production of curd from milk.

Try solving it in your notebook first, then check the solution.

medium

Analyze the story of Alexander Fleming's discovery of penicillin. Explain the chance observation, the microbes involved, and how this event demonstrates the principle of antibiosis.

Try solving it in your notebook first, then check the solution.

medium

Summarize the key events in the discovery of Penicillin, including the scientists involved and the microbial source.

Try solving it in your notebook first, then check the solution.

medium

Compare the roles of free-living nitrogen-fixing bacteria like Azotobacter and symbiotic nitrogen-fixing bacteria like Rhizobium in their function as biofertilisers.

Try solving it in your notebook first, then check the solution.

medium

Analyze the process of secondary sewage treatment. Explain how microbial activity reduces the Biochemical Oxygen Demand (BOD) and describe the fate of the microbial 'flocs' after the aeration stage.

Try solving it in your notebook first, then check the solution.

medium

Recall the bioactive molecule produced by the fungus Trichoderma polysporum and state its primary use.

Try solving it in your notebook first, then check the solution.

medium

A farmer wants to reduce the use of chemical pesticides for controlling butterfly caterpillars on his brassica crops. Demonstrate how the application of Bacillus thuringiensis (Bt) can serve as an effective biocontrol agent in this scenario.

Try solving it in your notebook first, then check the solution.

medium

A food processing company wants to sell bottled fruit juices. Evaluate the necessity of using enzymes like pectinases and proteases in their production process compared to home-made juices.

Try solving it in your notebook first, then check the solution.

medium

Demonstrate how methanogens, such as Methanobacterium, are utilized in the production of biogas and simultaneously play a crucial role in the nutrition of cattle.

Try solving it in your notebook first, then check the solution.

medium

Explain how Bacillus thuringiensis (Bt) acts as a biocontrol agent against butterfly caterpillars.

Try solving it in your notebook first, then check the solution.

medium

Define Biochemical Oxygen Demand (BOD).

Try solving it in your notebook first, then check the solution.

medium

Compare the metabolic roles of Lactobacillus in curd formation and Saccharomyces cerevisiae in bread making, focusing on the primary products that cause the characteristic changes in milk and dough.

Try solving it in your notebook first, then check the solution.

medium

Apply the definition of an antibiotic to explain the dual meaning of the term: 'against life' in the context of pathogens but 'pro-life' in the context of humans.

Try solving it in your notebook first, then check the solution.

medium

Explain the key difference between alcoholic beverages produced with and without distillation, and provide one example for each category.

Try solving it in your notebook first, then check the solution.

medium

A patient suffering from a heart attack is administered Streptokinase. Justify the use of this bioactive molecule in this medical emergency.

Try solving it in your notebook first, then check the solution.

medium

Compare and contrast the industrial production of wine and whisky. Focus on the role of Saccharomyces cerevisiae and the key processing step that differentiates the two beverages.

Try solving it in your notebook first, then check the solution.

medium

Justify why wine and beer production does not require distillation, unlike whisky and rum.

Try solving it in your notebook first, then check the solution.

medium

Formulate an argument to convince a community to install a biogas plant, highlighting its dual benefits in energy production and waste management.

Try solving it in your notebook first, then check the solution.

medium

Define antibiotics and explain their meaning in the context of human welfare.

Try solving it in your notebook first, then check the solution.

medium

Design a public awareness campaign to promote the use of biofertilisers over chemical fertilisers among farmers in your region. Your design should include the key message, target audience, and proposed methods of dissemination.

Try solving it in your notebook first, then check the solution.

medium

Critique the conventional farming practice of using chemical pesticides and justify the switch to biocontrol agents like

\textit{Bacillus thuringiensis}

and

\textit{Baculoviruses}

.

Try solving it in your notebook first, then check the solution.

medium

Examine the biochemical function of statins, which are produced by the yeast Monascus purpureus, and explain how they benefit human health.

Try solving it in your notebook first, then check the solution.

hard

The text mentions that "no man-made technology has been able to rival the microbial treatment of sewage." Critique this statement by considering the advantages and potential limitations of microbial sewage treatment, and propose one area where technology could enhance this biological process.

Try solving it in your notebook first, then check the solution.

hard

List two examples of free-living nitrogen-fixing bacteria and two examples of nitrogen-fixing cyanobacteria that act as biofertilisers.

Try solving it in your notebook first, then check the solution.

hard

Three water samples were tested for Biochemical Oxygen Demand (BOD). The values recorded were

250 \text{ mg/L}

,

15 \text{ mg/L}

, and

10 \text{ mg/L}

. The samples are known to be untreated sewage water, relatively clean river water, and secondary effluent from a sewage treatment plant (STP). Analyze these results to assign the correct label to each BOD value and justify your reasoning.

Try solving it in your notebook first, then check the solution.

hard

A farmer has a choice between using chemical nitrogen fertilisers and using a biofertiliser containing

\textit{Rhizobium}

and

\textit{Azotobacter}

. Evaluate the long-term ecological and economic impacts of both choices on the farm's soil health and crop yield.

Try solving it in your notebook first, then check the solution.

hard

Describe the process of secondary or biological treatment of sewage. Mention the role of flocs and Biochemical Oxygen Demand (BOD).

Try solving it in your notebook first, then check the solution.

hard

Design an experiment to demonstrate that the puffed-up appearance of dough is due to microbial fermentation and the production of

\text{CO}_2

gas. Include a control setup in your design.

Try solving it in your notebook first, then check the solution.

hard

Propose a method to increase the efficiency of a sewage treatment plant (STP) that is currently overwhelmed by the volume of waste water, without building an entirely new plant.

Try solving it in your notebook first, then check the solution.

hard

Evaluate the statement: "The discovery of antibiotics was the single most important contribution of microbes to human welfare." Justify your stance by comparing it with at least two other major microbial contributions discussed in the chapter.

Try solving it in your notebook first, then check the solution.

hard

Contrast the mechanism of action of a broad-spectrum chemical pesticide with that of a biocontrol agent like a baculovirus. Analyze the ecological impact of each, focusing on specificity and effect on non-target organisms.

Try solving it in your notebook first, then check the solution.

Microbes in Human WelfareClass 12 Biology Practice Questions