The diagram below five genes, including their enhancers, from the genome of a certain species. Imagine that pink, blue, green, black, grey and dark blue activator proteins exist that can bind to the approximately colour-coded control elements in the enhancers of these genes.

(a) Draw an X above enhancer elements (of all the genes) that would have activators bound in a cell where only gene five is transcribed. Identify which coloured activators would be present.

(b) Draw a dot above all enhancer elements that would have activators bound in a cell where the green, blue, and yellow activators are present. Identify which gene(s) would be transcribed.

(c) Imagine that genes 1, 2, and 4 codes for nerve-specific proteins, and genes 3 and 5 are skin-specific. Identify which activators would have to be present in each cell type to ensure transcription of the appropriate genes.

Enhancers are the DNA segment present in the DNA that activates the process of transcription. Activators are the protein that enhances the transcription process in addition to the enhancer. Transcription is the mechanism that converts the gene into mRNA.

The enhancers present in all genes are marked with the symbol ‘X.’ All gene segments in gene 5 have the activator segments that trigger the transcription process of gene 5. The dark blue, blue, and grey are enhancer segment that has activators bound in them.

The blue, green, and pink colors are the activators per the given condition. Gene 1, 2, 3, and 4 have the activator attached at the enhancer segment’s beginning and the end. But the gene 5 possesses the activation in the middle segment. Therefore, only four genes are transcribed per this condition.

Gene 1, 2, and 4 are nerve-specific coding genes. The activators present in the genes are in color, such as pink, green, blue, and black. These activators are responsible for activating the transcription of nerve-specific genes.

Gene 3 and 5 are the skin-specific genes. The activators present in these genes are in color: grey, black, dark blue, and blue. These activators activate the skin-specific genes to get transcribed.