The four nitrogenous bases commonly found in DNA are:

Which of these nitrogenous bases is not found in $\mathrm{RNA}$?

Which nitrogenous base is found in $\mathrm{RNA}$ but not in $\mathrm{DNA}$?

Which of the following molecules in a cell contains nitrogen?

Which of the following nucleotide bases are present in equal amounts in $DNA$ due to base pairing rules?

Select a correct structure for U.

Draw a structure for cytosine.

Draw 1 tautomeric form of thymine.

Draw the other 2 tautomeric forms of cytosine.