In natural systems, nitrogen is lost by denitrification. predict which of the following processes will be most responsible for replacing lost nitrogen in an ecosystem.

a) erosion

b) fixation

c) combustion

d) weathering

B) Fixation
The remaining processes do not help the Nitrogen content in the soil very much.

1.989×10^30 kg is the weight of the sun.

What is the difference between cytokinesis in plant and animal cells? animal cells dived by a cleavage furrow. plant cells divide by a cell plate that eventually becomes the cell wall. cytoplasm and cell membranes are necessary for cytokinesis in both plant and animals.