Describe the structure of human DNA (4 marks)
- 2 strands: Intertwine to form a double-helix structure Phosphodiester bonds between between phosphate group and pentose sugar of nucleotides - 4 Bases: Cytosine, Guanine, Adenine, Thymine. Complementary base pairing: A-T, C-G Hydrogen bonding between complementary bases Extra marks (for safety): purines (A,G), pyrimidines (C,G)
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