Which observation proves that a cellis a eukaryote?

a. it has a cell membrane

b. it contains ribosomes.

c. it has dna inside a nucleus.

d. it contains dna

C. It has a DNA inside a nucleus

maritime tropical may be your answer.

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.