biology. helpppp?

Question

What would happen if an extra base was inserted during DNA replication? How would that affect the amino acid Sequence?

Answer 1

This would create a point mutation if it occured in an open reading frame, or single base error. It would result in a frame shift in the codons so the animo acid sequence encoded is wrong.

ATG CAT GTA TTA .......TGA
ATG CAT GTA aTT....... with one A added the TTA now reads ATT and every codon after is misread.

If it occurred in a protein binding site or other regulatory region it might alter the way the regulatory proteins bound the DNA or some other detail about the regulation of a genes transcription. This might block or change the frequency a gene is transcribed. The sequence is good but the volume of the protein made is altered up or down.

if it occurred in an intron or a region of palindromic or Alu repeats it may do very little. The only function I know of for the palindrome repeats is like in XY alignment. The Y would still be able to self edit so long as most of the palindrome aligned. But in theory it might alter the ability to edit for other errors so allow a cascade of mutations.
http://www.nature.com/nature/journal/v423/n6942/full/423810a.html