Which of the following factors affecting photosynthesis does not have a direct effect on the process?
$I$. Light
$II$. Water
$III$. Temperature
$IV$. Carbon Dioxide
Select the correct option.

Blackman's law is concerned with

Categorize the following factors affecting photosynthesis into internal and external factors:
$I-$ Light
$II-$ Temperature
$III-$ Age and size of leaf
$IV-$ Leaf orientation
$V-$ Mesophyll cells and chloroplasts
$VI-$ $CO_2$ concentration
$VII-$ Water
$VIII-$ Chlorophyll content
$IX-$ Internal $CO_2$ concentration
Identify the correct sequence for internal factors and external factors respectively.

Identify the incorrect sentences:
$(I)$ Humidity in the atmosphere is relatively higher in areas where light becomes a limiting factor for plants.
$(II)$ An increase in light intensity beyond a certain point causes the breakdown of chlorophyll,leading to a decrease in the rate of photosynthesis.
$(III)$ $C_4$ plants respond to higher temperatures and show higher rates of photosynthesis,while $C_3$ plants have a much lower temperature optimum.

Which abiotic factor is not essential for the early growth of a plant,but growth is sustained only in its presence?

Generally,atmospheric $CO_2$ is not a limiting factor for hydrophytes because...