Answer: The correct answer is option (b).
Explanation:
A cycle in science is defined as process or phenomena which reoccurs again after a certain interval of a time.
In a set of chemical reactions where reactant is regenerated as a product in the end. This regenerated reactant will again establish the same set of chemical reactions in a same the fashion continuously.
Krebs cycle: it is cycle which occurs during in cellular respiration which starts from acetyl-Co-A enzyme. In the end of cycle energy is released with regeneration of acetyl-Co-A enzyme which will further continue the cycle.
Calvin cycle: It is cycle which occurs in chloroplast during the process of photosynthesis which starts from carbon-dioxide. In the end sugar molecule is released with regeneration of carbon-dioxide molecule which will further continue the cycle.
Hence, Krebs cycle and Calvin cycle both are cycles of chemical reaction in which start over continually.
