Which group is not alike?

Chemosynthesis and photosynthesis are alike in that both

Choose the correct option:
$(1)$ The first product of the $C_3$ pathway in the Calvin cycle is $PGA / OAA$.
$(2)$ The primary acceptor of $CO_2$ in the $C_4$ pathway is $PEP / OAA$.

Which of the following products of Hill's reaction are used in Blackman's reaction?

Blackman demonstrated that increasing illumination increased the photosynthetic rate up to a point when $CO_2$ becomes limiting. If light was not limiting,temperature becomes limiting. Emerson found that maximum $CO_2$ fixation could be achieved with brief flashes of light. Mark the correct statement in the following:

Which of the following factors is essential for photosynthesis?