Explain how scientists know the oxygen level in the atmosphere because of plants.

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides