Question

An inducer...

1. binds to the operator and prevents the repressor from binding at this site.

2. is the same as a promoter

3. stimulates the synthesis of needed enzyme(s).

4. inhibits the synthesis of needed enzyme(s).

5. binds to the promoter and prevents the repressor from binding to the operator.

When an enhancer is bound to the DNA during gene expression , it

1. increases the stability of a specific mRNA.

2. stimulates transcription of a specific gene.

3. stimulates transcription of nearly all genes.

4. stimulates splicing of a specific mRNA.

5. stimulates splicing of nearly all mRNA's

Answer 1

Ans- An inducer- 3) stimulates the synthesis of needed enzymes.

Inducers bind to the repressors which in turn causes the change in shape and prevents them(repressors) to bind to the DNA. This leads to transcription and thus causes gene expression. This is how inducers stimulate the synthesis of needed enzymes.

Ans- When an enhancer is bound to the DNA during gene expression,it- 2) stimulates transcription of a specific gene.

Enhancers are short DNA regulatory sequences which when bound by specific proteins( activators or transcription factors), enhance the transcription of a specific gene.