Well, one is Oxygen/ O, which has an atomic mass of 15.999 and the atomic number is 8, Oxygen is essential for life because we need it to breathe, and the plants need it for photosynthesis. The next would be Carbon, whose atomic number is 6, and is also used in graphite and one of the major factors in making coal, which is an important fuel.
The 3'-end of the reverse primer (3'-TTGGCCAATGG---5') is complementary to the forward primer (5'---AACCGGTTACC-3') and thus reduces the ability of the primers to bind to the targeted DNA sequence. There is possibility of hairpin loop formation or primer dimmers formation
