The sequence of nucleotides in DNA that determines the sequence of amino acids in a polypeptide via an mRNA intermediate is known as genetic code.
The genetic code includes 64 possible permutations and combinations of three-letter nucleotide sequences that can be made from the four nucleotides in mRNA - A, U, G and C.
The genetic code is a triplet code. Three consecutive nucleotides in mRNA constitute a codon which codes for a particular amino acid.
Out of the 64 codons, 61 code for amino acids and the remaining three are stop codons which do not specify any amino acid.
Hence, genetic code is a set of rules which helps to decode the information stored in genetic material and determine the sequence of amino acids in a protein.
Genetic code does not decode the information stored in proteins.
Histones are proteins that wrap the DNA molecule around itself.