Digestive, respiratory and circulatory systems are all examples of what? A. single celled
B. multi celled
C. plant cell
D. animal cell
E. tissue
F. respiratory
G. transport system
H. nervous
I. digestive
J. muscular
K. skeletal
L. circulatory
M. cells
N. specialized
O. nutrients
P. grow
Q. respire

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse