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AP Biology
Chapters 7 (Mitosis), 9, 10, 11, 12
Unit Review
Read Chapter 12 (Focus more on Sections 12.2 – 12.4) and the attached articles. Using this
information and your knowledge from this unit, try to answer the following questions.
1. Understand the structure of DNA and how to ‘read’ a DNA sequence:
a. Determine anti-parallel strand
b. Determine mRNA that would be produced
c. Determine the protein sequence that would be produced
2. Understand the process of DNA replication using the Prokaryotic replication model
a. Know all the players and the mechanics of the progress
b. What issues does the replication machinery have to deal with?
i. Separating strands
ii. Synthesizing antiparallel strands
iii. Accuracy
3. Why have an RNA intermediate? Why not just read DNA directly?
4. What is the central dogma? Discuss the life cycle of a typical retrovirus. How does the discovery of
retroviruses require revision of the central dogma?
5. What are the roles of mRNA and tRNA in gene expression?
6. How does RNA polymerase differ from DNA polymerases? How are they similar?
7. Why is a lack of proofreading ability in RNA polymerase not so significant?
8. Contrast events of transcription in prokaryotes and eukaryotes.
9. Compare/constrast the general properties of the genomes of prokaryotes and eukaryotes.
10. What functions as the catalyst in peptide bond formation in the ribosome, rRNA or protein? How
does this support the RNA-first hypothesis?
11. A protein-coding gene in a eukaryote has three introns. How many different proteins could
theoretically be produced by alternative splicing of the pre-mRNA from this gene?
12. What are some ways in which posttranscriptional and posttranslational modifications may alter
protein structure and function?
13. What are some sources/causes of DNA mutations?
14. What are the possible outcomes of a point mutation?
15. Why are chromosomal mutations more severe?
16. What would be more significant from an evolutionary standpoint – a somatic or germline mutation?
Why?
17. In reference to Figure 11.6 – Summarize the 2 methods an organism may use to regulate a
metabolic pathway. Give one advantage and one disadvantage of each method.
18. What are key differences between an inducible system and a repressible system in prokaryotic
gene expression?
19. Prokaryotes use operons to regulate expression of several related genes. How do eukaryotes
coordinate transcription of related genes at the same time?
20. What modifications can be made to eukaryotic histones and what impact may each modification
have on gene expression?
21. What specific nucleotide is modified by methylation of DNA? What affect(s) may methylation of
DNA have on DNA packaging and gene expression? Give one example of this phenomenon in
eukaryotes.
22. In colorectal cancer, tumor suppressor genes are not active. This is an important factor resulting in
uncontrolled cell division. Two possible explanations for the inactive genes are: a mutation in the
coding region, resulting in an inactive protein, or epigenetic silencing at the promoter of the gene,
resulting in reduced transcription. How would you investigate these two possibilities?
23. Answer the Apply the Concept question on p. 224 from Chap 11.