1. 8.6 Gene Expression and Regulation TEKS 5C, 6C, 6D, 6E KEY CONCEPT Gene expression is carefully regulated in both prokaryotic and eukaryotic cells.

2. 8.6 Gene Expression and Regulation TEKS 5C, 6C, 6D, 6E Eukaryotes regulate gene expression at many points. Different sets of genes are expressed in different types of cells. Transcription is controlled by regulatory DNA sequences and protein transcription factors.

3. 8.6 Gene Expression and Regulation TEKS 5C, 6C, 6D, 6E RNA processing is also an important part of gene regulation in eukaryotes. mRNA processing includes three major steps.

4. 8.6 Gene Expression and Regulation TEKS 5C, 6C, 6D, 6E mRNA processing includes three major steps. –Introns are removed and exons are spliced together. –A cap is added. –A tail is added.

5. 8.6 Gene Expression and Regulation TEKS 5C, 6C, 6D, 6E Environmental factors influence gene expression, resulting in different cell types. Internal factors can affect cell differentiation. –Uneven distribution of proteins, mRNA, and organelles within a cell can affect gene expression. –Surrounding cells can influence one another by sending and receiving signal molecules.

6. 8.6 Gene Expression and Regulation TEKS 5C, 6C, 6D, 6E Factors in an organism’s external environment can also affect gene expression. –Too much oxygen in an organism’s environment can prevent transcription proteins from being made by the cells. –Temperature can influence gene expression. –Drugs or chemicals in the external environment can influence cell differentiation. –Light can change the way that genes are expressed.