Part $2(1$ point each$)$: Below are key experiments done in human cells that determined the exact location of the sequences in the BCL$11$A enhancer required for gene expression. Answer the following questions.

Previous work identified the location of the enhancer required to activate transcription of BCL$11$A$.$ In $2015,$ soon after CRISPR was first introduced to mammalian cell culture systems, Canver et al used CRISPR to delete the entire BCL$11$A enhancer. To determine the effects of

deleting the enhancer on gene expression and hemoglobin production, they used three different cell culture lines: a control, a BCL$11$A null mutation, and the cell culture line with the just the enhancer deleted. In each of these lines, they measured BCL$11$A expression levels and the amount of varying types of globins that were produced. Below are their results.

Figure $1.$ In panel B$,$ bright blue represents that amount of adult beta$-$globin that is produced, dark blue represents the amount of fetal gamma$-$globin that is produced. White and grey represent other types of globin that are rarely produced.

$11.$ Describe what happens to BCL$11$A expression in the BCL$11$A null and in the enhancer deleted cells.

$12.$ Describe what happens to beta$-$globin production in the BCL$11$A null and enhancer deleted cells.

$13.$ What do these results mean for the effects of BCL$11$A expression on beta$-$globin production?