Question

The process of copying the genetic information from one strand of DNA into RNA is termed as transcription. The principle of complementarity of bases governs the process of transcription, also except that uracil comes in place of thymine. Study the complete transcription unit given below and answer the following questions:

Describe the location of (C) and (D) in the transcription unit.

Hint:

RNA polymerase synthesizes the RNA strand using the template DNA strand, creating a complementary sequence that mirrors the coding strand (with uracil replacing thymine).

Answer 1

Location of (C) and (D) in a Transcription Unit 

(C) = Promoter

(D) = Terminator

1. Location of (C) - Promoter:

• The promoter is located at the 5′ end of the coding strand of DNA.
• It lies upstream of the transcription start site.
• It is the region where RNA polymerase binds to initiate transcription.

2. Location of (D) - Terminator:

• The terminator is located at the 3′ end of the coding strand.
• It lies downstream of the coding region.
• This is the site where transcription ends, and the RNA polymerase detaches.

Summary:

In a transcription unit:

• Promoter (C) marks the beginning of transcription.
• Terminator (D) marks the end of transcription.

These regulatory sequences ensure that the correct gene segment is transcribed into RNA.