Secondary succession is a process started by an event (example forest fire) that reduces an already established ecosystem
Answer:they won't for a pair
Explanation:Basically it all depends on process called complementary base pairing, the structure of thymine and adenine is such that it forms two hydrogen bonds and therefore pair up
2.guanine and cytosine have such structure that they form three hydrogen bonds and pair up
So Adenine complements only thymine and guanine complements cytosine and there aren't any chances of guanine pairing up with thymine.