Why specific pairing of base pair important?
It maintains the genetic code during replication. This is the basis for semi-conservative replication of DNA. If bases did not always pair with one and exactly one other base, you’d get a change in the sequence of bases. That means your DNA would not be the same as it used to be. We normally call that mutation, and mutations are generally NOT beneficial (they’re either deleterious or benign). Eventually, you’d accumulate so many mutations that the DNA would no longer code for functional proteins, and the cell would not be able to carry out metabolism. You’d get cell death and, eventually, death of the organism.
