Which one of the following is not a structural part of a transcription unit in DNA?
Which one of the following is not a structural part of a transcription unit in DNA?
The correct option is C The inducer
A transcription unit is a sequence of nucleotides in DNA that carries the information for encoding a single RNA molecule as well as the sequences required for its transcription namely a promoter, an RNA-coding sequence, and a terminator. The promoter is a DNA segment that serves to initiate transcription of a particular gene. They are present upstream near the transcription start sites of genes. The gene that codes for any RNA / protein product which does not serve as regulatory protein is known as structural genes. The lac z, lac y and lac genes in lac operon are the structural genes. The inducer is a molecule that binds to the repressor and causes conformational changes in repressor which in turn can no longer bind to the operator. Thus, inducer induces the expression of the structural gene. It is not part of an operon. Termination sites are present downstream the structural genes which serve to terminate the transcription. The correct option is A.
A transcription unit is a sequence of nucleotides in DNA that carries the information for encoding a single RNA molecule as well as the sequences required for its transcription namely a promoter, an RNA-coding sequence, and a terminator. The promoter is a DNA segment that serves to initiate transcription of a particular gene. They are present upstream near the transcription start sites of genes. The gene that codes for any RNA / protein product which does not serve as regulatory protein is known as structural genes. The lac z, lac y and lac genes in lac operon are the structural genes. The inducer is a molecule that binds to the repressor and causes conformational changes in repressor which in turn can no longer bind to the operator. Thus, inducer induces the expression of the structural gene. It is not part of an operon. Termination sites are present downstream the structural genes which serve to terminate the transcription. The correct option is A.
