Which is the initiator codon?

How many sense codons code for the $20$ known amino acids?

Khorana and his colleagues synthesized an $RNA$ molecule with a repeating sequence of $U$ and $G$ nucleotides. The $RNA$ sequence "$UGU\ GUG\ UGU\ GUG$" produced a tetrapeptide with alternating chains of cysteine and valine. The codons for cysteine and valine are, respectively:

Hargobind Khorana received the Nobel Prize for his work on:

The elongation of the polypeptide chain in protein synthesis is terminated by which of the following?

Select the incorrect statement$(s)$.
$i.$ Six codons do not code for any amino acid.
$ii.$ Codon is read in $mRNA$ in a contiguous fashion.
$iii.$ Three codons function as stop codons.
$iv.$ The initiation codon $AUG$ codes for methionine.