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).
Answer:
Genetic variation that alter gene activity or protein function can introduce different traits in an organism. If trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation (a process known as natural selection).
Pretty sure it’s all of the above