UPSC Prelims 2021 GS Paper I · Q69 of 98 General Science easy

Consider the following : 1. Bacteria 2. Fungi 3. Virus Which of the above can be cultured in artificial/synthetic medium?

  1. (a) 1 and 2 only ✓ UPSC's answer
  2. (b) 2 and 3 only
  3. (c) 1 and 3 only
  4. (d) 1, 2 and 3

Why the answer is (a)

• Bacteria (1) and fungi (2) are cellular organisms with their own metabolism, so they grow on artificial media such as nutrient agar, broth or Sabouraud agar.

• Viruses (3) are obligate intracellular parasites lacking ribosomes and metabolic machinery; they can multiply only inside living host cells (cell cultures, embryonated eggs or animals), never in a synthetic medium.

• This is why vaccine viruses are grown in Vero cells or chicken eggs.

• Hence 1 and 2 only, option (a).

Why the other options are wrong

(b) 2 and 3 only
Viruses cannot grow in synthetic media.
(c) 1 and 3 only
Viruses need living cells; fungi can be cultured.
(d) 1, 2 and 3
Viruses cannot be cultured in artificial media.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2021, held on 10 October 2021. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

Practise this paper free