AP BIOLOGY CHAPTER GUIDECh. 12 - Molecular Biology of the Gene

1. In the middle of the unraveling the mysteries of DNA, researchers knew that genetic material must

be able to _______________________________ . It must be stable so it _____________________

with high accuracy and able to _________________________________ called mutations that

provide genetic variability required for evolution to occur. (p. 215)

2. Summarize the events of the Griffith transformation experiment. (figure 12.1)

1. __________________________________________________________________________

____________________________________________________________________________

2. __________________________________________________________________________

____________________________________________________________________________

3. __________________________________________________________________________

____________________________________________________________________________

4. __________________________________________________________________________

____________________________________________________________________________

3. What important conclusion was made from the transformed bacteria in the final test? (p. 215)

__________________________________________________________________________________

__________________________________________________________________________________

AP BIOLOGY CHAPTER GUIDE

4. 1944, Colin MacLeod and Maclyn McCarty concluded what about the Streptococcus bacteria in the

Griffen experiment? (p. 216) (summarize)

1. __________________________________________________________________________

____________________________________________________________________________

2. __________________________________________________________________________

____________________________________________________________________________

3. __________________________________________________________________________

____________________________________________________________________________

4. __________________________________________________________________________

____________________________________________________________________________

5. What three components do all nucleotides contain? (p. 217)

__________________ ____________________ __________________

6. What are the four nucleotides found in DNA? (p. 217)

___________ which binds with ______________ ; ______________ which binds with _____________

7. Describe Chargaff’s rules: (p. 217)

1. __________________________________________________________________________

2. __________________________________________________________________________

AP BIOLOGY CHAPTER GUIDE

8. Deoxyribose (the DNA sugar) is a ring-shaped molecule with an oxygen atom and ____

carbons. DNA has directionality because the phosphate is located on the _____ end of the sugar

whereas the hydroxyl (OH) is located on the _____ end of the sugar. (figure below and figure 12.3)

9. The Watson and Crick Model of DNA suggest that the two strands of the double helix are

_________________ which means the sugar-phosphate groups chained together are oriented in

opposite directions. We call these the 5’ end and the 3’ end in reference to the location of the

phosphate and hydroxyl groups (p. 218)

10. Look at this figure on the right.

Notice how adenine (A) and guanine

(G) have two rings. These are known

as the purines bases. Cytosine (C)

and thymine (T) have one ring. These

are called pyrimidine bases. What type

of bonds connect these bases together

and which base pair (C=G or A=T) is

stronger?

__________________________________________________________________________________

__________________________________________________________________________________

AP BIOLOGY CHAPTER GUIDE

11. Describe the term semiconservative replication. (p. 220)

__________________________________________________________________________________

__________________________________________________________________________________

12. Summarize the overall steps of DNA replication. (p. 220)

1. __________________________________________________________________________

____________________________________________________________________________

2. __________________________________________________________________________

____________________________________________________________________________

3. __________________________________________________________________________

____________________________________________________________________________

13. What is the role of DNA polymerase in replication?

__________________________________________________________________________________

14. DNA replication is quite a process! This will take a lot of practice to capture all the intricacies. Let’s

summarize the seven steps on p. 221.

1. __________________________________________________________________________

____________________________________________________________________________

2. __________________________________________________________________________

____________________________________________________________________________

3. __________________________________________________________________________

____________________________________________________________________________

4. __________________________________________________________________________

____________________________________________________________________________

5. __________________________________________________________________________

____________________________________________________________________________

6. __________________________________________________________________________

____________________________________________________________________________

AP BIOLOGY CHAPTER GUIDE

7. __________________________________________________________________________

____________________________________________________________________________

15. What are two differences between RNA and DNA? (p. 223)

__________________________________________________________________________________

__________________________________________________________________________________

16. Define the three main types of RNA. (p. 223) (NOTE: we’ll learn more of these in this chapter)

a. messenger RNA (mRNA) - ____________________________________________________

b. transfer RNA (tRNA) - ________________________________________________________

c. ribosomal RNA (rRNA) - ______________________________________________________

AP BIOLOGY CHAPTER GUIDE

17. Before you read on, don’t lose sight of the overall process of

protein synthesis. You start with __________, which is transcribed

into ____________ which then carries instructions to the ribosome

to build chains of _____________ which result in ____________ .

18. Describe the processes of transcription and translation.

(p. 223-224)

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

19. Describe the difference between a template strand and a gene strand in producing mRNA. (p. 225)

__________________________________________________________________________________

20. What is the role of RNA polymerase what direction is the gene strand made? (p. 225)

__________________________________________________________________________________

21. What is a promoter and where is it located? (p. 225)

__________________________________________________________________________________

22. Summarize the steps of initiation, elongation, and termination in the production mRNA. (p.226)

a. initiation - _________________________________________________________________

b. elongation - _______________________________________________________________

c. termination - _______________________________________________________________

23. How can an organism produce the multiple copies of the same mRNA transcript at the same time

and what benefit would it provide the organism? (p.226)

__________________________________________________________________________________

__________________________________________________________________________________

AP BIOLOGY CHAPTER GUIDE

24. Before mRNA can be exported out of the nucleus, it has to undergo processing. Describe the

structure and function of the 5’ cap and the poly-A tail. (p. 226)

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

25. Define the terms intron and exon. Which one of these will be removed before mRNA leaves the

nucleus? (p. 226 and diagram below)

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

26. Explain the role of splicosomes, snRNA’s, and ribozymes in RNA processing. (p. 227)

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

27. What role do introns play in alternatively splicing mRNA?

______________________________________________________

______________________________________________________

______________________________________________________

28. Describe the role of miRNA’s.

______________________________________________________

______________________________________________________

______________________________________________________

AP BIOLOGY CHAPTER GUIDE

29. How can introns help in creating variation and evolution in genes? (p. 227)

__________________________________________________________________________________

__________________________________________________________________________________

30. What is translation? (p. 228)

__________________________________________________________________________________

31. What role does tRNA play in translation? (p. 228)

__________________________________________________________________________________

32. Sketch a simplified version of figure 12.14. Include the 3’ end site attachment for an amino acid,

hydrogen bonding between the bases, and the anticodon - codon interaction.

33. Define the terms codon and anticodon. (p. 228)

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

34. What does the wobble hypothesis ensure. (p. 229)

__________________________________________

__________________________________________

__________________________________________________________________________________

35. What is a ribosome primarily composed of? _____________ . Where can ribosomes go once

synthesized?(p. 229) ________________________________________________________________

AP BIOLOGY CHAPTER GUIDE

36. Summarize the steps of translation. (pgs. 230-231 and figures 12.16, 12.7, 12.8)

Initiation

1. ______________________________________

______________________________________ ______________________________________

______________________________________

2. ______________________________________

______________________________________ ______________________________________

______________________________________

Elongation

1. ______________________________________

______________________________________ ______________________________________

______________________________________

2. ______________________________________

______________________________________ ______________________________________

______________________________________

1

2

1 2

AP BIOLOGY CHAPTER GUIDE

Elongation

3. ______________________________________

______________________________________ ______________________________________

______________________________________

4. ______________________________________

______________________________________ ______________________________________

______________________________________

Termination

1. ______________________________________

______________________________________ ______________________________________

______________________________________

2. ______________________________________

______________________________________ ______________________________________

______________________________________

3 4

1

2

AP BIOLOGY CHAPTER GUIDE

37. Summarize the events of protein synthesis in eukaryotes using figure 12.19 (and below)

1. __________________________________________________________________________

2. __________________________________________________________________________

3. __________________________________________________________________________

4. __________________________________________________________________________

5. __________________________________________________________________________

6. __________________________________________________________________________

7. __________________________________________________________________________

8. __________________________________________________________________________

1

2 3

4

5

6

7

8

AP BIOLOGY CHAPTER GUIDE

38. Define the terms associated with the structure of a chromosome. (p. 233-234)

a. histone - __________________________________________________________________

b. nucleosome - _____________________________________________________________

c. euchromatin - ______________________________________________________________

d. heterochomatin - ___________________________________________________________

39. Identify the five levels of chromosome organization using figure 12.20.

1. __________________________________________________________________________

2. __________________________________________________________________________

3. __________________________________________________________________________

4. __________________________________________________________________________

5. __________________________________________________________________________