Question

Legume plants are important for the atmosphere because they
(A)Help in ${ N }{ 0 }_{ 2 }$ fixation
(B)Do not help in ${ N }{ 0 }_{ 2 }$ fixation
(C)Increase soil fertility
(D)Help in ${ N }_{ 2 }$​ fixation

Answer 1

Hint: Legume plants are important for the atmosphere because they help in fixing the gas which is colorless, odorless, and is a diatomic in its natural form. It has a molar mass of 28.0134 g/mol.

Complete answer:
Legume plants are important for the atmosphere because they Help in ${ N }_{ 2 }$​ fixation. Biological nitrogen fixation- It is that the process that changes inert ${ N }_{ 2 }$ into biologically useful ${ N }{ H }_{ 3 }$. This process is mediated in nature only by Nitrogen-fixing rhizobia bacteria.

Additional Information: Legume nitrogen fixation starts with the first step of the formation of a nodule. The fixed nitrogen isn't free; the plant must contribute a big amount of energy within the sort of photosynthate (photosynthesis-derived sugars) and other nutritional factors for the bacteria. Almost all of the nitrogen which is fixed goes directly into the plant. However, some nitrogen is often “leaked” or “transferred” into the soil (30–50 lb N/acre) for neighboring non-legume plants. Most of the nitrogen eventually goes back to the soil for plants growing in the surrounding when vegetation (roots, leaves, fruits) of the legume dies and decomposes. In a new field, there is mostly poor fixation, which is usually attributed to the shortage of native rhizobia to nodulate the legume, but the cause can also be improper plant nutrition or other plant stresses that inhibit nitrogen fixation.
So, the correct answer is ‘Help in ${ N }_{ 2 }$​ fixation’.

Note: Nitrogen is so vital because it's a significant component of chlorophyll, the compound by which plants use sunlight energy to provide sugars from water and ${ C }{ O }_{ 2 }$ (i.e., photosynthesis). It's also a significant component of amino acids, the building blocks of proteins. Without proteins, plants wither and die.