9 Nitrogen Bases Adenine always combines with Thymine Guanine always combines with Cytosine
10 DNA Sugar = Deoxyribose The sugar and the phosphate group of the chain and the nitrogen bases stick out like teeth on a zipper
11 DNAThe stands of the molecule are made of alternating bonds of sugar and phosphate.The bases are connected to the sugar and held together by a weak hydrogen bond.
12 History of DNAJames Watson & Francis Crick formulated the model for DNA.Rosalind Franklin had taken many x-rays/pictures.
13 DNA Replication DNA copied during Interphase in the chromosomes 1. Hydrogen bonds break at the nitrogen base pairs2. Strands unzip3. Free floating nucleotides bond to the single strands4. Product is 2 molecules of DNA