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Mention a product of human… (Class 12 Biology 2026, Q25)

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BiologyCBSE Class 12 · Board exam 2026, set 57/5/1 · 3 marks · Short answer

CBSE Class 12 Biology 2026: question 25

Set in the CBSE Class 12 board exam of 2026, paper 57/5/1, section C, question 25, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q25 · 3 marks · Short answerMicrobes in Human Welfare

Mention a product of human welfare obtained with the help of each one of the following :
(a) Saccharomyces cerevisiae
(b) Propionibacterium shermanni
(c) Aspergillus niger
(d) Trichoderma polysporum
(e) Acetobacter aceti
(f) Streptococcus

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 57/5/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Recall the NCERT chapter 'Microbes in Human Welfare': household products, industrial organic acids and bioactive molecules.

Hint 2

Two of these make organic acids, one makes a cheese, and two make medicines.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. (a) Saccharomyces cerevisiae (brewer's/baker's yeast): bread/bakery products, or ethanol and alcoholic beverages.

    ½ mark

  2. (b) Propionibacterium shermanni: Swiss cheese (its CO₂ produces the large holes).

    ½ mark

  3. (c) Aspergillus niger: citric acid.

    ½ mark

  4. (d) Trichoderma polysporum: cyclosporin A, an immunosuppressive agent used in organ-transplant patients.

    ½ mark

  5. (e) Acetobacter aceti: acetic acid (vinegar).

    ½ mark

  6. (f) Streptococcus: streptokinase, a 'clot buster' enzyme used to dissolve clots in blood vessels.

    ½ mark

Answer: (a) Bread/ethanol; (b) Swiss cheese; (c) Citric acid; (d) Cyclosporin A; (e) Acetic acid; (f) Streptokinase

Where the marks are

  • Bread / ethanol / beverages (½ mark)
  • Swiss cheese (½ mark)
  • Citric acid (½ mark)
  • Cyclosporin A (½ mark)
  • Acetic acid (½ mark)
  • Streptokinase (½ mark)

Revise the chapter

Practise this chapterBoard-style questions from Microbes in Human Welfare, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 57/5/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.