Exam 3 potential answers

1. When and how was DNA discovered?
-DNA was discovered in 1928 through the Griffith experiment (testing 2 different kind of S.pneumococcus bacteria on mice).
-nhung nguyen
2. What questions did the Griffith experiment answer?
why do organism have the traits they have? and what chemical is responsible for traits being heritable are the questions.c
-Hoa Le

3. List some of the properties of DNA.
bases held together in string by "sugar-phosphate backbone"
double-stranded with antiparallel strands
-Hoa Le

4. What is meant by saying DNA has "antiparallel strands"?
point in opposite direction
-Hoa Le

5. What bases are paired together?
A&T, C&G

6. What type and how many bonds hold each complementary base-pair together?
Hydrogen bond are hold the base-pair together.
A=T C=-G (triple bond)
-Hoa Le

7. What are two different ways to gram-stain?

8. What patches together the Okazaki fragments and what falls off chromosomes at terminal site?
Okazaki fragments patched together by DNA LIGASE. DNA polymerase fall of at terminal site.
-Hoa Le

9. What are the leading and lagging strand in DNA replication?
Leading strand is one strand synthesised continuosly lone long stand with no breaks.
Lagging strand is synthesis discontinously.
-Hoa Le

10. What de-interlocks chromosomes in DNA replication process?
topoisomerase iv
-Hoa LE

11. At the oriC site is there more A and T or G and C? Why?
More AT because it contain weaker H-bond
-Hoa Le

12.What direction must DNA be replicated? Per copy how much of the DNA is new?
DNA replicated in 5-3 direction. half is new.
-Hoa LE

13. What binds to the oriC site during replication?

14. how do humans protect themselves against viruses?
Immune defenses, vaccination
-Hoa Le

15. What is smallpox?
-smallpox are large virus, double-stranded DNA genome, cause fever.
-Hoa Le

16. What traits must a disease have for it to be potentially eradicable?

by keeping the microbe from spreading for 1 cycle
-nhung nguyen

17. what are biofilms? What are they made of?
Biofilms dense layers of lipids, protein and sugar
-Hoa Le

18. what is the AI for all gram negative bacteria?
Homoserine lactone (HSL)
-Hoa LE

19. Explain the Griffith experiment.

20. DNA can be replicated in which direction?
-Hoa Le

21. What attaches to the replication bubble to unzip DNA at the replication bubble?
-Hoa Le

22. why do viruses use host cell enzymes to copy viral DNA?
-Because viruses do not have the enzymes to make DNA
-Hoa Le

23. What is the differences between PA01 and JP2 bacteria?
JP2 does not have AI gene
-Hoa Le

24. What is the oriC site?
where DNA start replication process.
-Hoa Le

25. How does DNA replication start?
by using helicase DnaA bind to bases at oriC ON BACT CHROMOSOME
-Hoa Le

26. Does DNA start with 5' or 3'?
-Hoa Le

27.What are the Okazaki fragments and what do they patch together?
okazaki fragments are DNA pieces that separated by RNA primers in the lagging strand, and they are patched together by DNA ligase
-nhung nguyen

28. Describe the steps of DNA… fun!

29. How fast does E. Coli replicate DNA? How is this useful?
15min. so they can mutated faster.
-Hoa Le

30. What is a mutation and how does it affect the genome? Good or bad?
Mutation is the change in DNA sequence usually neutral but can be good.
mutation change the base of genome
-Hoa Le

31. Why do viruses have small genomes? How do viruses use host enzymes to copy viral DNA?
small because they dont have own gene for replication enzymes. More reliant on other organism more reduction in genome.
-Hoa Le

32. How do vaccinations work and why don't people get the virus once they have a vaccination?
Vaccination get an acquired immune response, but don't get illness./ Because their body immune to the virus
-Hoa Le

33. How can we keep microbes from spreading to wipe them out forever?
by keep microbe from spreading for 1 cycle.
-Hoa Le

34. What are the three kinds of point mutations and how do they differ?
1.Missense: just one base in DNA sequence is change, thus change a.a.s sequence
2.Nonsense: just one base in DNA sequence is change, thus early stop codon in mRNA led to short protein
3.Silent: change to DNA but no change in a.a.s sequence.
-Hoa Le

35. Explain how artificial transformation works?

36. What does comk gene allow bacteria to do?
comk gene allow bact to take up DNA from the environment.
-Hoa Le

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