Water is

Give scientific reasons:
$(1)$ Green plants form the basis of life on Earth.
$(2)$ Photosynthesis is a complex metabolic process.

In which of the following cell organelles do both photo-chemical and thermo-chemical reactions occur?

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:

Plants are known as purifiers of air due to the process of:

Consider the following statements regarding photosynthesis and respiration in plants and select the correct option.
$I$. RuBisCO has high affinity to oxygen in low $CO_2$ concentration.
$II$. The Calvin pathway occurs in the chloroplast of bundle sheath cells of $C_4$ plants.
$III$. Yeast poison themselves when the concentration of alcohol reaches $7\%$.
$IV$. Oxygen is a final hydrogen acceptor during aerobic respiration.