Question

Path of dark reaction of photosynthesis was traced through the use of

• A. ${}^{32}$P
• B. ${}^{14}$CO${}_2$
• C. ${}^{18}$O${}_2$
• D. X-rays

Answer 1

Answer: (B)

${}^{14}$CO${}_2$

Calvin and his co-workers by using the isotope of C that is ${}^{14}C$ to trace the path of the carbon fixation in light reaction. Due to his discovery, the cycle is known as the Calvin cycle which is the common path for all plants in the photosynthesis.

So the correct option is '${}^{14}C$'.