Concept Map Connections:

Griffith → Avery → Hershey-Chase → Watson-Crick → Chargaff: Each experiment built on the previous: Griffith showed transformation exists → Avery identified the molecule (DNA) → Hershey-Chase physically confirmed it → Watson-Crick determined DNA's structure → Chargaff's rules explained base pairing in the structure.

Replication → Transcription → Translation: The central dogma flows from one to the next. Replication ensures DNA is faithfully copied. Transcription converts selected DNA sequences to RNA. Translation converts RNA code to protein. All three use the same template-directed, antiparallel synthesis principle.

DNA Structure → Replication Mechanism: Antiparallel strands explain why leading strand is continuous (3'→5' template = can follow fork) and lagging strand is discontinuous (5'→3' template = must work backward). The structure directly dictates the mechanism.

Chargaff's Rules → Base Pairing → Semiconservative Replication: Because A must always pair with T (and G with C), when strands separate during replication, each single strand automatically templates for a perfectly complementary new strand — this is the molecular basis of semiconservative replication.

Lac Operon → Gene Expression → Evolution: The lac operon shows that gene expression is regulated to match metabolic needs (economical). Only when lactose is the available carbon source and glucose is absent are the lactose-metabolizing enzymes produced. This regulatory precision was selected by evolution as it conserves energy.