Microbes in Human Welfare

Name the microorganism from which each of the following is obtained and state its use: (i) an antibiotic, (ii) a beverage, (iii) an organic acid, (iv) an immunosuppressant, (v) a blood-cholesterol-lowering agent.

What is biogas? Name the group of microbes responsible for its production and state the major component of biogas.

What are biofertilizers? Explain the role of (i) Rhizobium and (ii) mycorrhiza in enhancing soil fertility.

Explain the role of microbes in the secondary (biological) treatment of sewage. What are flocs?

Describe the primary and secondary treatment of sewage in a sewage treatment plant. What is activated sludge, and what happens to it afterwards? Why is BOD important?

Explain the use of (i) Bacillus thuringiensis and (ii) Trichoderma as biocontrol agents in agriculture.

Name the microorganism used to produce the alcohol in bread and beer, and state the product it releases that makes dough rise.

Who discovered penicillin and from which microorganism is it obtained? Explain how antibiotics have improved human health.

How many marks is Microbes in Human Welfare worth in the Class 12 board exam?

Around 4 marks of the 70-mark CBSE Biology theory paper, based on the official unit-wise weightage. Microbe → product table — guaranteed easy marks.

Is Microbes in Human Welfare easy or hard?

It's rated easy — one of the easier chapters in Class 12 Biology. Most students need about 2 hours to cover it well.

What should I focus on in Microbes in Human Welfare?

Going by the board papers themselves, the recurring areas are Microbial Products, Biogas, Biofertilizers, Sewage Treatment, Biocontrol — that's where the marks actually sit.

What questions come from Microbes in Human Welfare in board exams?

Between 2019–2024, CBSE board papers asked questions from this chapter on Microbial Products, Biogas, Biofertilizers, Sewage Treatment — 1- to 5-mark questions.