Which of the following is the initiator codon?

Under which of the following conditions will there be no change in the reading frame of the following $mRNA$: $5'-AACAGCGGUGCUAUU-3'$?

Find the nucleotide sequence of $mRNA$ which codes for the sequence of amino acids 'Met-Leu-Val-Arg' and choose the correct option from below:

The genetic code of the checkerboard (codon table) is not applicable to which of the following?

How many base additions or deletions do not change the reading frame?

There is only one possible sequence of amino acids when deduced from a given nucleotide sequence. However,multiple nucleotide sequences can be deduced from a single amino acid sequence. Explain this phenomenon.