POGIL Biology I Introduction to Life on Earth

POGIL 7 biol 212 – Genetic engineering

Model 1, Fig. 18.2 9th edition- gene splicing Model 2 – Fig. 18.6 9th edition. Plasmids and genetic engineering (genetic engineering is also referred to as recombinant DNA technology) Using the diagrams above, your textbook, and your note set, answer the following questions. 1. Model 1 shows two DNA molecules. Point them out with an arrow on your diagram.

2. In model 1, pencil in the 5’phosphate and 3’ hydroxyl designations at ends of the DNA molecules in the diagram.

3. What is EcoR1, and what does it do to a DNA molecule?

4. Indicate the sticky ends in model 1with an arrow and label. Why are these regions of DNA referred to as ‘sticky ends’? Add 3’ and 5’ designations to the sticky ends.

5. According to model 1, which enzyme covalently links (or seals) the sticky ends together?

6. In the final step shown by model 1, sticky ends are ligated, or sealed, so to speak. Chemically speaking, what occurs between the 5’ phosphate and 3’ hydroxyl during ligation?

7. Model 2 shows a DNA sample and a group of plasmids. What macromolecule are the plasmids? 8. What is the source of the DNA in the DNA sample shown in model 2?

9. The second step of model 2 shows that the DNA sample and plasmids have been ‘cleaved’. Which type of protein did this cleaving?

10. In the third step, fragments from the DNA sample are joined to plasmids. Using the knowledge you gained through study of model 1, explain how this occurs.

11. Step 4 of model 1 shows a shallow plate containing bacterial colonies. How many colonies are on the plate? What is a colony?

12. At the very bottom of model 2, there are five oblong objects containing plasmid+sample DNA. What are these objects? In relation to the plate of colonies, where did each of these objects come from? 13. Are the pieces of sample DNA in each of the plasmids shown in the last illustration identical or different? How do you know?

14. What is the purpose of joining the sample DNA to the plasmid and then introducing it into E. coli?

15. What are some of the things you might do with the sample DNA now that you can grow large quantities of it?