For leucine (leu) which codes are correct?

Production of human protein in bacteria by genetic engineering is possible because

How many genetic codes specify the amino acid proline?

Match List-$I$ with List-$II$ and select the correct option:

List-$I$	List-$II$
$(p)$ $UUU$	$(1)$ $Pro$
$(q)$ $AAA$	$(2)$ $Gly$
$(r)$ $CCC$	$(3)$ $Phe$
$(s)$ $GGG$	$(4)$ $Lys$

Which of the following $m-RNA$ sequences can be completely translated into a polypeptide chain?
$(a)\ 5'-AUG\ UGA\ UUA\ AAG\ AAA-3'$
$(b)\ 5'-AUG\ AUA\ UUG\ CCC\ UGA-3'$
$(c)\ 5'-AGU\ UCC\ AGA\ CUC\ UAA-3'$
$(d)\ 5'-AUG\ UAC\ AGU\ AAC\ UAG-3'$

The chemical method developed by which of the following scientists was instrumental in synthesizing $\text{RNA}$ molecules with defined combinations of nitrogen bases?