<prompt> Equal number of nucleotide bases are seen between which pair of nucleotides:AGGTGCAC  <response>: Ans. c GCRef: Harpers Biochemistry; 30th ed. pg. 360-361Chargaffs Rules for Double stranded ds DNA In all cellular DNAs regardless of species-- Number of adenosine residues is equal to no. of thymidine residues i.e. AT.- No. of guanosine residues is equal to no. of cystidine residues GC From these relationship it follows that sum of purine residues- AGTC- Ratio of purine to pyrimidine is always around 1.TCAG -1 - The base composition of DNA generally varies from one species to another- DNA specimens isolated from different tissues of same species have the same base composition.- The base composition of DNA in a given species does not change with an organisms age, nutritional state or changing environment. 