Which of the following groups of organisms does not produce $O_2$ during photosynthesis?

Which of the following photosynthetic bacteria possess both $PS-I$ and $PS-II$?

Which statement is correct for photosynthesis?

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 statements is incorrect?

Find the incorrect statement$(s)$ about photosynthesis from the following:
$A$. The water-splitting complex is associated with $PS-I$.
$B$. $C_4$ plants use the $C_3$ pathway of $CO_2$ fixation as the main biosynthetic pathway.
$C$. In $C_4$ plants, photorespiration does not occur.
$D$. $C_3$ plants exhibit 'Kranz' anatomy.
$E$. $ATP$ synthesis in chloroplast occurs through chemiosmosis.