10. Chargaff established some rules about the composition of bases in DNA, fill in the blanks. 3PTS a) Number of b) Number of Cytosine = Number of c) BUT [ A ] + [ T ] = Number of Thymine [ G ] + [ C ] 11. The DNA molecule is a double helix composed of 2 chains that spiral around each other forming a pair of right/left -handed helices and are. parallel/antiparallel. Write in the correct answer. 1PT 12. State the 3 primary functions of DNA. 2PTS .