Question

Which plant has the highest rate of photosynthesis?

Answer 1

Photosynthesis is the process responsible for the production of oxygen from plants by consuming carbon dioxide. Carbon dioxide is the substrate for plants in photosynthesis and oxygen is the product released into the atmosphere. Oxygen forms the basis of respiration and energy in cells. If photosynthesis does not take place, there won’t be any release of oxygen into the atmosphere. Oxygen is the life of the earth. It is present everywhere, including in oceans. It is the source of respiration for humans and most animals.

Complete answer:
The $C4$ plants show a high rate of photosynthesis. The photosynthetic rate in those plants is known to be directly related to the variation of the solar rays in the daytime. The maximum rate of photosynthesis occurs in the blue and red regions of the visible light. Corn, sorghum and sugarcane fall into $C4$ plants. These are of economic importance as they have comparatively higher photosynthetic efficiencies in comparison to other plants.
In these plants, exchange of gases with the atmosphere is seen in their surroundings through pores known as stomata. When stomata open, carbon dioxide diffuses in to be utilized for photosynthesis and oxygen, a product of the process diffuses out. During this time, plants lose water due to transpiration. This increases in hot and dry climates. Plants that perform $C4$ photosynthesis can leave their stomata closed more time than the $C3$ counterparts as $C4$ plants are relatively efficient in incorporation of carbon dioxide. This helps in minimizing the loss of water.

Note:
$C4$ plants are the plants in which carbon dioxide is fixed first into a compound, which consists of four carbon atoms before making entry into the Calvin cycle of photosynthesis. The maximum photosynthesis takes place in the blue and red region of visible light, which is done by the absorption of chlorophyll a and chlorophyll b. The absorption peak of the pigments is at $480$nm (blue light) and $680$nm (red light) region of the spectrum.