Question

Plants with high light compensation points are
A. ${C_3}$ plants
B. Sun plants
C. Shade plants
D. Mesophytes

Answer 1

The light compensation point is that light intensity observed on the light curve where the rate of photosynthesis is exactly the same as that of respiration.
There is no need for exchange of gases from outside i.e. carbon dioxide of respiration completes requirements of photosynthesis and Oxygen of photosynthesis meets the requirement of respiration is called light compensation point.

Complete answer:
The light compensation point is the light intensity on the light curve where the rate of photosynthesis exactly matches the rate of cellular respiration. At this point the uptake of carbon dioxide through photosynthetic pathways is equal to the respiratory release of carbon dioxide, and the uptake of oxygen by respiration is equal to the photosynthetic release of oxygen.
At the compensation point, the total carbon dioxide assimilation is zero.
Leaves release carbon dioxide by photorespiration and cellular respiration, but carbon dioxide is also converted into carbohydrate by photosynthesis.
For Example: In the early morning and late evenings, the compensation point may be reached as photosynthetic activity decreases and respiration increases.
Therefore, the partial pressure of carbon dioxide at the compensation point also known as gamma.
It is a function of irradiation.
The intracellular concentration of carbon dioxide affects the rates of photosynthesis and photorespiration.
Higher carbon dioxide concentrations favor photosynthesis whereas low carbon dioxide concentrations favor photorespiration.
For example: Sun plants that are having high light intensity.

So, the correct option is option B. Sun plants.

Note: The compensation point is reached during early mornings and late evenings.
Respiration is relatively constant but photosynthesis depends on the intensity of sunlight.
When the rate of photosynthesis equals the rate of respiration then, occurs the compensation point.