Mutation introduces new genes into a species and brings about the changes in

If the $DNA$ codons are $ATG\ ATG\ ATG$ and a cytosine base is inserted at the beginning,which of the following will result?

The chromosome shown in the diagram below is broken at the points which are indicated by the arrows and the genes between these points become inverted. The resulting order of the genes will be:

Assertion: An organism with lethal mutation may not even develop beyond the zygote.
Reason: All types of gene mutations are lethal.

If the gene sequence on a chromosome changes from $abcdefg$ to $abcfedg$,what is this phenomenon called?

Explain frame-shift mutation.