Which of the following describes a properly controlled experiment

Which element forms the basis of all organic organisms a carbon b oxygen c hydrogen d nitrogen

Eutrophication caused by human nutrient pollution.

Label the steps for protein synthesis in order, beginning with the first steponce the protein is made, the gene for a particular trait is expressedmrna joins the ribosome, and the anticodons from trna join mrna to form a chain ofamino acidsrna polymerase unzips dna and free rna nucleotides join dna to form mrnav a chain of amino acids is formed from peptide bonds, creating a proteinmrna is transported from the nucleus of the cell to the ribosomes of the cell.