Answer:
Cytosine & Guanine
Explanation:
Living organisms contain in their cell a biomolecule responsible for the storage and transmission of genetic information called NUCLEIC ACID. DNA is one of the two nucleic acids found in living cells. However, the DNA molecule is a polymer made up of monomeric units called NUCLEOTIDES.
Nucleotides of a DNA are made up of three components namely: 5-carbon sugar (deoxyribose), phosphate group, and a nitrogenous base (Adenine, Guanine, Cytosine and Thymine). Hence, based on the question, Cytosine & Guanine are the components (nitrogenous base) found in the DNA of all living organism.