Give a comparison between ${ C }{ 3 }$ and ${ C }{ 4 }$ pathway.

Hint: Some plants are found in temperate regions while some plants are found in warm regions. So, according to the environmental conditions, different plants have a different mechanism of production of energy and oxygen.

Complete answer:

Additional Information: ${ C }{ 3 }$ Pathway: ${ C }{ 3 }$ plants use the Calvin cycle or ${ C }{ 3 }$ cycle for the dark reaction of photosynthesis. The majority of the plants on the earth are ${ C }{ 3 }$ plants and exhibit ${ C }{ 3 }$ pathway. The plants are called ${ C }{ 3 }$ because of the production of phosphoglycerate which is 3 carbon compounds. Photosynthesis occurs when the stomata are open. ${ C }{ 4 }$ Pathway: ${ C }{ 4 }$ plants use Hatch-slack pathway or ${ C }{ 4 }$ cycle for the dark reaction of photosynthesis. ${ C }{ 4 }$ plants are very less in number as compared to ${ C }{ 3 }$ plants. The plants are called ${ C }{ 4 }$ because of the production of oxaloacetate which is 4 carbon compounds. Photosynthesis occurs even when the stomata are closed.

Note: There is a specialized structure present in ${ C }{ 4 }$ plant which is known as Kranz anatomy. In these i.e ${ C }{ 4 }$ plants, mesophyll cells cluster around a bundle-sheath cell in the form of a ring. The entire structure plays an important role in ${ C }{ 4 }$ photosynthesis.