Anoxygenic photosynthesis is characteristic of

Choose the correct pair:

Most abundant protein of the biological world is

Which of the following 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:

$A -$ Productivity of $C_3$ plants is higher than $C_4$ plants.
$R -$ Photorespiration occurs in $C_3$ plants.