Write out the full name for dna. what is a gene? where in the cell are chromosomes located? dna can be found in what two organelles? what two scientists established the structure of dna? what is the shape of dna? what are the sides of the dna ladder made of? what are the "rungs" of the dna ladder made of? what sugar is found in dna? in rna? how do the bases bond together? the two purines in dna are dna is made of repeating units called why is rna necessary to act as a messenger? why can't the code be taken directly from the dna? proteins are made where in the cell? how do some cells become brain cells and others become skin cells, when the dna in all the cells is exactly the same. in other words, if the instructions are exactly the same, how does one cell become a brain cell and another a skin cell? why is dna called the "blueprint of life"?