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Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceBIOLOGYMicrobes in Human Welfare1 Mark
Question
Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true but reason is not the correct explanation of assertion.
  3. Assertion is true but reason is false.
  4. Both assertion and reason are false.
Assertion: Curdling is required in the manufacture of cheese.
Reason: Lactic acid bacteria and rennet is used for the purpose.
✓

Answer

  1. Both assertion and reason are true but reason is not the correct explanation of assertion.

Solution:

The manufacture of cheese requires two main steps curdling and the ripening. Curdling the milk proteins forms a solid material from which the liquid is drained away. The curdling process may be exclusively microbiological, since acid production of lactic acid bacteria is sufficient to coagulate milk proteins. However, an enzyme known as rennin (extracted from the stomachs of calves or rennet) which curdles milk is often used for this purpose.

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