A student wants to modify model 1 so that it represents an RNA double helix instead of a DNA double helix. Of the following possible changes, which would be most effective in making model 1 look more like RNA than DNA?

By modification of the deoxyribose to ribose sugar in the DNA molecule, you can obtain a single-strand RNA sequence

The student should add - OH to the deoxyriboses, transforming them into riboses.

In addition, it would be necessary to remove the nitrogen base Timina and put the nitrogen base Uracila in place.

Explanation:

As you already know, DNA and RNA are nucleic acids with many similarities and many differences as well.

One of the most striking differences is that DNA has two strands intertwined, while RNA has only one strand. However, in the question above, we see that the student has a double-stranded DNA model, which he wants to look like a double-stranded RNA. For that he must make two modifications:

First, it is important to realize that DNA is called deoxyribonucleic acid, because it does not have the "-OH" molecule in its sugar molecule. On the other hand, RNA (ribonucleic acid) has this molecule. For this reason, it is necessary to add "-OH" molecules to all sugar molecules in the DNA model, transforming that molecule into ribose (the sugar present in RNA).

In addition, DNA and RNa are formed by the same nitrogenous bases, with the exception of thymine (which only exists in DNA) and uracil (which only exists in RNA), so it is necessary that all thymines present in the DNA model replaced by uracil.