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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: Vitamins B2 is found in cereals, green vegetables, brewer's yeast, egg white, milk and liver.
Reason: Vitamins B2 can be commercially produced by some yeasts.
✓

Answer

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

Solution:

Besides cereals, green vegetables, brewer's yeast, egg white, vitamin B2 is also produced by intestinal bacteria. The vitamin was first obtained in 1938 using wild strain of mould Ashbya gossypii. Vitamin B2 is essential for normal growth and reproduction in a number of laboratory animals. It is essential for the maintenance of good health in humans. Better strains of the mould have been discovered which give 100-300 times more yield of the vitamin than the original one. Other sources include yeast cells, Eremothecium ashbyii, Clostridium species.

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