This lecture introduces the molecular biology background necessary for genomic data analysis, covering topics such as DNA structure, genes, proteins, RNA, DNA replication, transcription, translation, and the genetic code. It explains the central dogma of molecular biology, the process of DNA duplication, and the mechanisms of intron splicing and alternative splicing. The lecture also delves into nucleic acid hybridization and the polymerase chain reaction (PCR) technique for DNA amplification.