Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Molecular Basis of Inheritance

Question:

Identify the regions of the transcription unit.
(A) Promoter
(B) Sigma factor
(C) Terminator
(D) The structural gene
Choose the correct answer from the options given below:

Options:

(A), (B) and (D) only

(A), (B) and (C) only

(A), (C) and (D) only

(B),(C) and (D) only

Correct Answer:

(A), (C) and (D) only

Explanation:

The correct answer is Option (3)- (A), (C) and (D) only

The process of copying genetic information from one strand of the DNA into RNA is termed as transcription.However, unlike in the process of replication, which once set in, the total DNA of an organism gets duplicated, in transcription only a segment of DNA and only one of the strands is copied into RNA .

A transcription unit in DNA is defined primarily by the three regions in the DNA : (i) A Promoter (ii) The Structural gene (iii) A Terminator .

A) Promoter - This region signals the starting point of transcription and provides a binding site for RNA polymeras

(C) Terminator - This region signals the end of transcription.

(D) The structural gene - This region contains the sequence that will be transcribed into RNA.

The Sigma factor is not a region of the transcription unit; rather, it is a protein subunit of bacterial RNA polymerase that helps in recognizing the promoter region.