Which Term Represents the Region of Soil Influenced by Plant

Question

Which term represents the region of soil influenced by plant roots? 
A) stele 
B) cortex 
C) root cap 
D) rhizoplane 
E) rhizosphere

Accepted Answer

The rhizosphere is the region of soil that is influenced by plant roots, where there is a high level of microbial activity and nutrient exchange. The other options are specific parts of the root itself: the stele is the central vascular cylinder, the cortex is the outer layer of the root, and the root cap is the protective layer at the tip of the root. The rhizoplane is the surface of the root itself, but does not encompass the surrounding soil.