# 8.12. Gene Explorer Tool¶

The Gene Explorer (GeneX), from the biology department at UMB, simulates the transcription, splicing, processing, and translation of a small hypothetical eukaryotic gene. GeneX allows students to make specific mutations in a gene sequence, and it then calculates and displays the effects of the mutations on the mRNA and protein.

Specifically, the Gene Explorer does the following:

1. Finds the promoter and terminator
2. Reads the DNA sequence to produce the pre-mRNA
3. Finds the splice sites
4. Splices and tails the mRNA
5. Finds the start codon
6. Translates the mRNA

## 8.12.1. Gene Explorer Code¶

<problem>
<p>Make a single base pair substitution mutation in the gene below that results in a protein that is longer than the protein produced by the original gene. When you are satisfied with your change and its effect, click the <b>SUBMIT</b> button.</p>
<p>Note that a "single base pair substitution mutation" is when a single base is changed to another base; for example, changing the A at position 80 to a T. Deletions and insertions are not allowed.</p>
<script type="loncapa/python">
if ans=="CORRECT": return True
import json