As a consequence a cell must have the ability to make RNA before it can make DNA .
The deoxyribonucleotides used to make DNA are made from ribonucleotides , the building blocks of RNA , by removing the 2 ' - hydroxyl group .
As a consequence a cell must have the ability to make RNA before RNA can make DNA .
The deoxyribonucleotides used to make DNA are made from ribonucleotides , the building blocks of RNA , by removing the 2 ' - hydroxyl group .