DNA<span> and </span>RNA<span> are nucleic acids found in the cells of living organisms. ... The </span>synthesis<span> of </span>proteins<span> starts with transcribing the instructions in </span>DNA<span> into mRNA. The mRNA is then carried out of the cell's nucleus into the cytoplasm, specifically into structures called ribosomes.</span>
The answer is that the criteria of classification change whith the improved understanding of organisms around us
The nucleus is in the middle of a cell
and it controls the different part of the cell
sorry what this means¯\_(ツ)_/¯