2019 Year 12 IB Extended Essays

4. According to the graph, take note of other cell types that have similar or higher levels of expression. If it is clear that the expression is very low compared to other cell types, write ‘low expression in heart’, eliminate this transcription factor and move on to the next. 5. Return to the result page and click on the magnifying glass button to view the numerical data of the graph. 6. Under the ‘SAMPLES’ column, calculate the average figure of the ‘signal’ that is listed for heart muscle cells and then find 90% of the average figure 7. Compared the 90% figure with other tissue types that express similar levels of the transcription factor. If at least one quarter of the samples that are at least 90% of the average signal of hear muscle cells, write the name of the tissue in the table under the column ‘other cell types that expresses it’. 8. Repeat steps 3 to 7 for all the graphs that are available for the transcription factor. 9. Repeat steps 2 – 8 for all the other transcription factors selected for heart muscle cells. Although some transcription factors may seem to be an appropriate choice in reprogramming, it is important to ensure that the particular transcription factors will not cause negative side effects to the cell. For example, some transcription factors may be associated with causing cancer or other diseases. All the results obtained from this section of the procedure will be recorded under the column ‘Known functions’. Possible defects: 1. Access the NCBI Gene database at: https://www.ncbi.nlm.nih.gov/gene and search for the first transcription factor (Baf60c) and click on the result for humans (Homo sapiens). 2. Under the ‘summary’ section, record the processes that are the gene involved in and if defects in the gene are disease causing. Add any information in the table under the column ‘Known functions. 3. Repeat steps 1 and 2 for every transcription factor in the table Signalling pathways: 1. Open a browser on the computer and enter the url: https://www.genome.jp/kegg/pathway.html to access the Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway Database. 2. Enter the name of the first transcription factor (Baf60c) in the search bar and click ‘Search’. 3. Click on the thumbnail image for each of the results and look at the pathway results for each of the transcription factors. Examine the cellular processes that the transcription factor is involved in, and 2.3 Investigating possible undesirable effects

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