Answer
Item from Fig. 18.8 -- Category in Fig. 21.6
Enhancer -- Regulatory sequences
Proximal control elements -- Regulatory sequences
Transcription start site -- Regulatory sequences/exon
Exon -- Exons
Intron -- Introns
PolyA signal sequence -- Regulatory sequences
Transcription termination region -- Regulatory sequences
Work Step by Step
See Ch. 18, including the text near Fig. 18.8 which describes the job of each part labelled at the top of Fig. 18.8. Most of the parts control transcription or RNA stability, making them regulatory sequences.
