During photorespiration, the phosphoglycolate (PGO) produced by RuBP oxygenation is eventually converted to PGA; 75% of the carbon in PGO is recovered. How many molecules of PGO are required to generate two molecules of PGA through this route?
a. five
b. four
c. three
d. two
e. one

B). Four.

Explanation:

Photorespiration is demonstrated as the respiratory process that involves a light-dependent release of carbon-dioxide and uptake of oxygen in photosynthetic organisms that helps in completing the Calvin cycle.

As per the question, 'four' molecules of PGO(phosphoglycolate) is required to produce the two molecules of PGA through the given route as one-fourth of them are lost during the process in the form of Carbon-dioxide due to the chain of reactions. Thus, option B is the correct answer.

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