Which of the following is an example of positive regulation of gene expression?

• A. Transcription is halted on a specific gene to limit the amount of protein being created by the gene's expression.
• B. The protein that is translated is immediately degraded by the cell before it can serve its function.
• C. Elongation of translation comes to a stop and the ribosome dissociates when a regulatory protein binds.
• D. A protein binds to DNA and then stimulates the initiation of transcription of a specific gene.

Answer: (D)

Verified step by step guidance

1. Understand the concept of gene expression regulation: Gene expression can be regulated at various stages, including transcription, translation, and post-translation. Positive regulation involves mechanisms that increase the expression of a gene.
2. Identify the key feature of positive regulation: Positive regulation typically involves the activation or enhancement of gene expression. This can occur when a protein or other molecule binds to DNA and promotes the transcription of a gene.
3. Analyze the given options: Review each option to determine which one describes a scenario where gene expression is increased or stimulated.
4. Option analysis: The first three options describe scenarios where gene expression is reduced or halted, which are examples of negative regulation. These include halting transcription, degrading proteins, and stopping translation.
5. Identify the correct example: The last option describes a protein binding to DNA and stimulating transcription initiation, which is a classic example of positive regulation of gene expression.