conserved sequence

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conserved sequence Any sequences of bases (or amino acids) in comparable segments of different nucleotides (or proteins) that tends to show similarity greater than that due to chance alone. For example, if one position is occupied by the same base in all comparable DNA sequences, then that position is said to be completely conserved. If the same base occurs at a given position in, say, 75% of samples examined, it would be described as partially conserved. By extension, the conservation of other positions in a sequence is assessed in the same way, usually by computer analysis. The degree to which sequences are conserved can indicate the extent of structural and functional similarities between different genes or between different proteins and provides clues to their possible evolutionary relations (see homologous).