NEET 1991 · Class 11

Photosynthesis in Higher Plants

Which technique has helped in investigation of Calvin cycle?

  1. (A)X-ray crystallography
  2. (B)X-ray technique
  3. (C)Radioactive isotope technique
  4. (D)Intermittent light

The NCERT line that answers it

Verbatim line

He along with J.A. Bassham studied reactions in green plants forming sugar and other substances from raw materials like carbon dioxide, water and minerals by labelling the carbon dioxide with $C^{14}$ .

Chapter
Photosynthesis in Higher Plants
Section
intro PHOTOSYNTHESIS IN HIGHER PLANTS
Page
1
Words matched
30 of 31

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

How this line gives the answer

0, emb=0.8666, combined=0.5199). Verified: high — The span explicitly mentions 'labelling the carbon dioxide with C¹⁴', which is a radioactive isotope technique used to study the Calvin cycle, directly matching option C.

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Question text is reproduced from the published NEET 1991 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.