NEET 2009 · Class 11

Biological Classification

57. T.O. Diener discovered a

  1. (A)free infectious DNA
  2. (B)infectious protein
  3. (C)bacteriophage
  4. (D)free infectious RNA

The NCERT line that answers it

Verbatim line

In 1971, T.O. Diener discovered a new infectious agent that was smaller than viruses and caused potato spindle tuber disease.

Chapter
Biological Classification
Section
2.6 VIRUSES, VIROIDS, PRIONS AND LICHENS
Page
11
Words matched
42 of 42

The answer appears as a continuous sentence in NCERT. This is that sentence.

How this line gives the answer

0, emb=1.0, combined=1.0). Verified: high — The span explicitly states 'It was found to be a free RNA' which directly matches the correct answer 'free infectious RNA' and distinguishes it from the other options.

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Every one traced to the exact sentence in NCERT that answers it, including 90% of the 2026 paper. Sit a mock on the real NEET 2027 computer interface and every mark you drop comes back with its line attached.

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Question text is reproduced from the published NEET 2009 paper for study and commentary. NCERT text is quoted, not redistributed; textbooks remain at ncert.nic.in. Our mapping method, including its measured error rates, is published at /methodology.