Skip to Videos All | Section 1 | Section 4 | Reflections | Section 1, • 9/10/26 Section 1: Instructional Audio DNA topology, Branched DNA junctions, Reciprocal Exchange, DNA Knots, DNA Half-Turns & Nodes/Crossings, DNA Helical Conformations (A-DNA, B-DNA, Z-DNA), Switchback-based Trefoil Knot.