Biotech quiz 1

Artificial Selection vs Genetic Engineering

1. Artificial selection = ? Example? → Humans breed for traits (dogs, corn).

2. Genetic engineering = ? Example? → Direct DNA change (insulin in E. coli, Golden Rice).

3. Key difference? → Selection = slow, uses existing traits. Engineering = fast, precise, can add new genes.

4. Downside: Artificial selection? → Inbreeding, less diversity.

5. Downside: Genetic engineering? → Off-target effects, ethics, ecological risks.

6. Dogs vs insulin — which method? → Dogs = selection; Insulin = engineering.

Ancient Biotechnology

7. Ancient food biotech? → Fermentation (bread, beer, yogurt).

8. Ancient crop/animal biotech? → Selective breeding/domestication.

9. Ancient plant technique? → Grafting fruit trees (combine traits).

4 Fields of Biotechnology

10. Four fields? → Medical, Agricultural, Industrial, Environmental.

11. Medical example? → Insulin, vaccines, gene therapy.

12. Agricultural example? → Bt corn, herbicide-tolerant soy.

13. Industrial example? → Enzymes, antibiotics, biofuels.

14. Environmental example? → Bioremediation (oil spills, wastewater).

Restriction Enzymes

15. Restriction enzyme = ? Source? → Bacterial protein that cuts DNA at specific sites.

16. Recognition site? → Short DNA sequence, often palindrome (e.g., GAATTC).

17. Sticky vs blunt ends? → Sticky = overhangs (easy join). Blunt = flat cuts (harder).

18. EcoRI cuts where? → GAATTC → G^AATTC (sticky ends).

19. Which type used in labs? → Type II (predictable cut sites).

DNA Ligase

20. DNA ligase = ? → Enzyme that “glues” DNA, seals backbone.

21. Lab ligase & energy source? → T4 ligase, uses ATP.

22. How to improve ligation? → Use sticky ends, higher DNA concentration, overnight at low temp.

Plasmids

23. Plasmid = ? → Small circular DNA, replicates independently.

24. Why useful? → Gene cloning, protein production, delivery vector.

25. Selectable marker? Example? → Lets plasmid cells survive (ampicillin resistance).

26. MCS/polylinker? → Cluster of restriction sites for easy DNA insertion.

27. Cloning vs expression vector? → Cloning = store DNA; Expression = make protein.

28. Copy number = ? → Plasmid copies/cell (high = lots of DNA, low = stable).

Cloning Workflow

29. Steps of cloning? → Cut DNA → Ligate into plasmid → Transform into bacteria → Select → Screen.

30. Blue-white screening? → Blue = no insert; White = insert present.

31. Confirm clone? → PCR, restriction digest, sequencing.

32. Dephosphorylate vector = why? → Stops self-ligation (forces insert in).