Microbiology of Soils
Nitrogen fixation

fix the free nitrogen (N2) by which it should not be usable by plants
both (a) and (b)
changes the free nitrogen (N2) to a form usable by plants
especially changes nitrogen compounds, mostly amines such as NH2

ANSWER DOWNLOAD EXAMIANS APP

Microbiology of Soils
A heterocyst is

a cell that carries out oxygenic photosynthesis
a type of spore
the progenitor of cyanobacterial vegetative cells
a terminally differentiated cell that fixes nitrogen

ANSWER DOWNLOAD EXAMIANS APP