Question

which of the following statements about this enhancer is correct?
the enhancer codes for a small protein.
the enhancer is within the sequence that codes for the mrnas 5 untranslated region.
the enhancer codes for a large protein.
the enhancer is associated with a protein when the gene is being transcribed.

Explanation:

1. Recall the function of an enhancer: An enhancer is a regulatory DNA sequence. It does not code for proteins (so options about coding for small/large proteins are wrong). Also, it is not part of the mRNA - coding sequence (so the option about being in the 5' untranslated region - coding sequence is wrong).
2. The correct property: Enhancers function by binding to specific transcription factors (proteins) when the associated gene is being transcribed, to enhance the rate of transcription. So the statement "The enhancer is associated with a protein when the gene is being transcribed" is correct.

Answer:

The enhancer is associated with a protein when the gene is being transcribed.