Answer:Adenine and guanine are purine bases found in both DNA and RNA. ... What is the nitrogenous base displayed in the computer model? ... Click the button below to examine the structure of a nucleotide triphosphate.
Explanation:
The reason scientists believe this is that there was basically no oxygen in the atmosphere at this time, which meant that cells needed to be anaerobic to survive,<span> going around the problem of no oxygen in the atmosphere.
Hope this helps.</span>