Answer: They contain DNA and RNA, they can exhibit a wide range of lifestyles, and they are essential to almost every ecosystem.
Explanation:
G always pairs with C...So, if there is 30% G, then there's 30% C...which is 60%...that leaves 40% A+T - and you have to split this up too - so 20% Thymine (T) and 20% Adenine (A).
