Explain how cell signaling pathways in prokaryotes and eukaryotes demonstrate conservation of major features over time

Eukaryotic cells and prokaryotic cells are distant living things as they have differences even on the cellular level (i.e. the presence of a nuclear membrane, rRNA differences). Although even with these differences, the molecular biology especially for cellular metabolism and signaling pathways are conserved. One of the more common signaling pathway that is seen in both prokaryotes and eukaryotes is the G-protein pathway which involves a seven pass or serpentine protein with an intrinsic GTPase activity (hence the name) which then signal either the production of cAMP or IP3/DAG wherein these second messengers will activate certain protein kinases that will phosphorylate specific proteins and enzymes and regulate cells’ function. 

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion