How many genetic codes specify the amino acid proline?

One codon codes for only one amino acid,hence the code is

How many types of $t-RNA$ are present in the cytoplasm?

The terms $Gene$ and $Cistron$ are sometimes used as synonyms because:

Give scientific reasons: Unambiguous,universal,and degenerate are some of the terms used for the genetic code.

Based on your understanding of the genetic code,explain the formation of an abnormal hemoglobin molecule. What are the known consequences of such a change?