Karnataka 2nd PUC Biology Chapter 8 Microbes in Human Welfare Important Questions 2027

Students often find Karnataka 2nd PUC Biology Chapter 8 difficult because Microbes in Human Welfare covers several applications, processes and biological terms that can be confusing during exam revision. Practising chapter-wise questions can help strengthen concepts such as curd and cheese making, sewage treatment, biogas, biocontrol agents and biofertilisers. The Karnataka 2nd PUC Biology Chapter 8 Important Questions 2027 include important questions with answers, along with quick revision tables.

Before practising, students should check the Karnataka 2nd PUC Syllabus 2026-27 to review the prescribed topics. The Karnataka 2nd PUC Exam Pattern 2027 can also help you understand marks and question types

Karnataka 2nd PUC Biology Chapter 8 Microbes in Human Welfare Important Questions

Karnataka 2nd PUC Biology Chapter 8 Important Questions cover key concepts from Microbes in Human Welfare through chapter-based MCQs on food production, sewage treatment, biogas, biofertilisers and biocontrol agents.

Q1. Roquefort cheese is ripened by growing a specific fungus on it which gives it a particular _________.

• (A) Texture

• (B) Large holes

• (C) Flavour

• (D) Colour

Answer: (C) Flavour. The fungus is Penicillium roqueforti.

Q2. The fruit juices available commercially are clearer than ones which are homemade. Which ingredient is added in commercially available fruit juices?

• (A) Lipase and protease

• (B) Pectinase and hydrolase

• (C) Pectinase and protease

• (D) Hydrolase and protease

Answer: (C) Pectinase and protease.

Q3. Blood cholesterol lowering agents are known as _________.

• (A) Steroids

• (B) Statins

• (C) Lipolytics

• (D) Diuretics

Answer: (B) Statins. They come from Monascus purpureus.

Q4. The supernatant left after sedimentation of sewage water during primary treatment is known as

• (A) Affluent

• (B) Flocs

• (C) Sludge

• (D) Effluent

Answer: (D) Effluent.

Q5. What is BOD?

• (A) Bacterial Oxygen Demand

• (B) Biological Organic Debris

• (C) Biochemical Organic Demand

• (D) Biochemical Oxygen Demand

Answer: (D) Biochemical Oxygen Demand.

Q6. In an anaerobic sludge digester, during the digestion process, mixture of gases like _________ are produced.

• (A) CH4, H2O, O2

• (B) C2H6, H2S, CO2

• (C) CH4, H2O2, CO2

• (D) CH4, H2S, CO2

Answer: (D) CH4, H2S, CO2.

Q7. The depth of concrete tank, a part of biogas plant, ranges from _________ to _________.

• (A) 10–15 feet

• (B) 10–15 metre

• (C) 15–20 feet

• (D) 15–20 metre

Answer: (A) 10–15 feet.

Q8. Mycorrhiza absorbs _________ from soil and passes it to the plant.

• (A) K

• (B) P

• (C) Fe

• (D) Mg

Answer: (B) P (phosphorus).

Q9. A common biocontrol agent for the control of plant diseases is

• (A) Baculovirus

• (B) Bacillus thuringiensis

• (C) Glomus

• (D) Trichoderma

Answer: (D) Trichoderma.

Q10. Which one of the following is not a nitrogen fixing organism?

• (A) Anabaena

• (B) Nostoc

• (C) Azotobacter

• (D) Pseudomonas

Answer: (D) Pseudomonas.

Karnataka 2nd PUC Biology Chapter 8 PDF

The 2nd PUC Biology Chapter 8 PDF has the chapter-wise important questions for Microbes in Human Welfare with the answer key. Students can save it for offline revision before tests.

Solve the Karnataka 2nd PUC Previous Year Question Paper and the Karnataka 2nd PUC Model Papers 2026-27 to see how these questions appear in a real paper. The Karnataka 2nd PUC Mid Term Question Paper is also useful for timed practice.

Important Topics in Karnataka 2nd PUC Biology: Microbes in Human Welfare

Go through these points first, then try the questions again:

• Household Products: Lactobacillus turns milk into curd and raises vitamin B12. Baker's yeast ferments bread dough. Swiss cheese gets holes from CO2, and Roquefort cheese gets its flavour from a fungus.

• Industrial Products: Fermenters are very large vessels. Wine and beer need no distillation, while whisky, brandy and rum do. Also learn about antibiotics, organic acids, enzymes and statins.

• Sewage Treatment: Learn primary treatment (physical), secondary treatment (aeration, flocs, activated sludge), BOD and anaerobic sludge digesters.

• Biogas: Methanogens such as Methanobacterium make methane from cellulosic material. Remember the plant parts and the role of IARI and KVIC.

• Biocontrol Agents: Learn Bacillus thuringiensis, Trichoderma and Baculoviruses, and how each one works.

• Biofertilisers: Learn Rhizobium, Azospirillum, Azotobacter, Glomus and cyanobacteria with their uses.

Students who revise these six topics well can answer most of the 2nd PUC Biology Chapter 8 important questions with ease.

How to Prepare for Karnataka 2nd PUC Biology Chapter 8

A simple 5-step plan to revise this chapter fast:

1. Learn the names first: Microbes, their products and scientific names give the easiest marks. Write scientific names in italics or underline them.

2. Practise MCQs daily: Most questions in this chapter are fact-based, so short daily practice works well.

3. Draw and label: Practise the biogas plant diagram and the order of sewage treatment: primary, aeration, settling, sludge digestion.

4. Solve previous year papers: Many questions repeat with small changes.

5. Revise the table daily: Read the microbe and product table in the last week, and be careful with look-alike names such as Azotobacter and Acetobacter.

Karnataka 2nd PUC Biology Chapter 8 Important Questions 2027 cover household and industrial microbes, sewage treatment, biogas, biocontrol agents and biofertilisers in easy steps. Regular practice of the questions above will help you score full marks in Microbes in Human Welfare.

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