Question

Which genetic mutation would cause the most dramatic change in the genetic make-up of an individual?

A gene mutation that inserts one extra base pair into the genetic sequence

A mutation that deletes three consecutive base pairs from the genetic material

A base-pair substitution mutation where one base pair becomes another but codes for the same amino acid

A single point mutation that changes the codon for a different amino acid

Answer 1

I would say the first option is most drastic, tbh.

Answer 2

If you think about it the 2nd choice is rather bad because it is deleting a codon, and that will mean that all downstream codons will be out of order for protein synthesis.

However, I agree with @strawberrysorbet
This is because the removal or addition of a base pair will alter all downstream codons, they wont be in a different order; but rather will be completely different (assuming the addition isn't in a few very specific sections). Perhaps the worst case in this scenario is that because of the addition, the trailing 3 stop codons will only have 1-2 functioning stop codons which would cause the transcription/translation of the gene affected would actually mess up the sequence with the addition/deletion AND the next gene.

Answer 3

three-consecutive deletions or insertions of base-pairs is not often seen with drastic effect, because it does not affect the coding of protein outside the insertion.
any change in frameshift translation is the problem, and that can occur in one insertion or more than three-consecutive deletions/insertions
http://www.pearsonhighered.com/mathews/ch07/fi7p21.htm