In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Q: The human genome is stored on 23 chromosome pairs in the cell nucleus and in the small mitochondrial DNA .
A: 
The human genome is the complete set of nucleic acid sequences for humans , encoded as DNA within the 23 chromosome pairs in cell nuclei and in a small DNA molecule found within individual mitochondria .