The TATA box is composed of which repeating sequence?

The TATA box is composed of which repeating sequence?

• A. GC repeats
• B. TATA repeats
• C. ATG repeats
• D. CG repeats

Answer: (B)

AT-rich promoter regions are where transcription often begins in eukaryotes. The TATA box is defined by a sequence pattern rich in thymine and adenine, typically described as repeating “TATA” units. That repeated TATA sequence creates an AT-rich stretch that unwinds more easily, helping RNA polymerase II and transcription factors assemble at the start site. That’s why the best description is TATA repeats. GC repeats would make DNA more stable and aren’t characteristic of this promoter element; ATG repeats would point to a coding start codon motif, not a promoter sequence; CG repeats are associated with CpG islands and methylation, not the TATA box.

AT-rich promoter regions are where transcription often begins in eukaryotes. The TATA box is defined by a sequence pattern rich in thymine and adenine, typically described as repeating “TATA” units. That repeated TATA sequence creates an AT-rich stretch that unwinds more easily, helping RNA polymerase II and transcription factors assemble at the start site. That’s why the best description is TATA repeats. GC repeats would make DNA more stable and aren’t characteristic of this promoter element; ATG repeats would point to a coding start codon motif, not a promoter sequence; CG repeats are associated with CpG islands and methylation, not the TATA box.