Final answer:
The genetic code is maintained in a nucleotide sequence where three nucleotides (codons) encode for one amino acid. There are 64 possible codons but only 20 different amino acids, meaning the genetic code is degenerate, allowing for redundancy.
Step-by-step explanation:
The genetic code is encased in a nucleotide (nt) sequence, which is the sequence of nitrogen bases found in a DNA or RNA strand. To code for the 20 different amino acids found in polypeptides, a sequence of three nucleotides or a 'codon' is required. In DNA and RNA, sequences of three nitrogen bases (adenine (A), cytosine (C), guanine (G), and thymine (T) or uracil (U) in RNA) form these codons. Each codon specifies an amino acid, except in cases where they signal the start or end of protein synthesis. This set of three-nucleotide codons is what makes up the genetic code.
The genetic code is universal, which means the same genetic code is used across all organisms from viruses to humans. It is also described as degenerate, meaning that, while there are 64 possible codon combinations, there are only 20 amino acids, so multiple codons can code for the same amino acid. This is an efficient system as it allows for some redundancy and flexibility in the genetic code, thus preventing harmful effects from minor mutations.