AP/IB Biology Study Guide Chapters 18 - 21

1. List and describe the structural components of viruses
2. Explain why viruses are obligate parasites
3. Describe 3 patterns of viral genome replication
4. Explain the role of reverse transcriptase in retroviruses
5. Describe how viruses recognize host cells
6. Distinguish between lytic and lysogenic reproductive cycles using phage T 4 and phage λ as examples.
7. Outline the procedure for measuring phage concentration in a liquid medium
8. Describe several defenses bacteria have against phage infection
9. Using viruses with envelopes and RNA viruses as examples, describe variations in replication cycles of animal viruses
10. Explain how viruses may cause disease symptoms and describe some medical weapons used to fight viral infections
11. List some viruses that have been implicated in human cancers and explain how tumor viruses transform cells
12. Distinguish between horizontal and vertical routes of viral transmission in plants
13. List some characteristics that viruses share with living organisms and explain why viruses do not fit our usual definition of life
14. Provide evidence that viruses probably evolved from fragments of cellular nucleic acid
15. Describe the structure of a bacterial chromosome
16. Describe the process of binary fission in bacteria and explain why replication of the bacterial chromosome is considered to be semiconservative
17. List and describe the 3 natural processes of genetic recombination in bacteria
18. Distinguish between general transduction and specialized transduction
19. Explain how the F plasmid controls conjugation in bacteria
20. Explain how bacterial conjugation differs from sexual reproduction in eukaryotic organisms
21. For donor and recipient bacterial cells, predict the consequences of conjugation between the following
1. F + and F - cell
2. HFr and F - cell
22. Define transposon and describe 2 essential types of nucleotide sequences found in transposon DNA
23. Distinguish between an insertion sequence and a complex transposon
24. Describe the role of transponases and DNA polymerase in the process of transposition
25. Explain how transposons can generate genetic diversity
26. Briefly describe the 2 main strategies cells use to control metabolism
27. Explain why grouping genes into an operan can be advantageous
28. using the trp operon as an example, explain the concept of an operon and the functionof the operator, repressor, and corepressor
29. Distinguish between structural and regulatory genes
30. Describe how th lac operon functions and explain the role of the inducer allolactose
31. Explain how repressible and inducible enzymes differ and how these differences reflect differences in the pathways they control
32. Distinguish between positive and negative control and give examples of each from the lac operon
33. Explain how CAP is affect glucose concentration
34. Describe how E. coli uses the negative and positive controls of the lac operon to economize on RNA and protein synthesis

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1. Compare the organization of prokaryotic and eukaryotic genomes
2. Describe the current model for progressive levels of DNA packing
3. Explain how histones influence folding in eukaryotic DNA
4. Distinguish between heterochromatin and euchromatin
5. Using the Barr body as an example, describe the function of heterochromatin in interphase cells
6. Describe where satellite DNA is found and what role it may play in the cell
7. Describe the role of telomeres in solving the end-replication problem with the lagging DNA strand
8. Using the genes for rRNA as an example, explain how multigene families of identical genes can be advantageous for a cell
9. Using α-globin and β-globin genes as examples, describe how multigene families of nonidentical genes probably evolve, including the role of transposition
10. Explain the potential role that promoters and enhancers play in transcriptional control
11. Explain why the nuclear envelope in eukaryotes offers a level of post-transcriptional control beyond that found in prokaryotes
12. Explain why the ability to rapidly degrade mRNA can be an adaptive advantage for prokaryotes
13. Describe the importance of mRNA degradation in eukaryotes and describe how it can be prevented
14. Explain how gene expression may be controlled at the translational and post-translational level
15. Compare the arrangement of coordinately controlled genes in prokaryotes and eukaryotes
16. Explain how eukaryotic genes can be coordinately expressed and give some examples of coordinate gene expression eukaryotes
17. Provide evidence from studies of polygene chromosomes that eukaryotic gene expression is controlled at transcription and that gene regulation responds to chemical signals such as steroid hormones
18. Describe the key steps of steroid hormone action on gene expression in vertebrates
19. In general terms, explain how genome plasticity can influence gene expression
20. Describe the effects of gene amplification, selective gene loss, and DNA methylation
21. Explain how rearrangements in the genome can activate or inactivate genes
22. Explain the genetic basis for antibody diversity
23. Explain how DNA methylation may be a cellular mechanism for long-term control of gene expression and how it can influence early development
24. Describe the normal control mechanisms that can convert proto-oncogenes to oncogenes
25. Explain how changes in tumor-suppressor genes can be involved in transforming normal cells into cancerous cells
26. Explain how oncogenes are involved in virus-induced cancers

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Chapter 20

1. Explain how advances in recombinant DNA technology have helped scientists study the eukaryotic genome
2. Describe the natural function of restriction enzymes
3. Describe how restriction enzymes and gel electrophoresis are used to isolate DNA fragments
4. Explain how the creation of sticky ends by restriction enzymes is useful in producing a recombinant DNA molecule
5. Outline the procedures for producing plasmid and phage vectors
6. Explain how vectors are used in recombinant DNA technology
7. List and describe the 2 major sources of genes fro cloning
8. Describe the function of reverse transcriptase in retroviruses and explain how they are useful in recombinant DNA technology
9. Describe ho genes of interest can be identified with the use of a probe
10. Explain the importance of DNA synthesis and sequencing to modern studies of eukaryotic genomes
11. Describe how bacteria can be induced to produce eukaryotic gene products
12. List some advantages for using yeast in the production of gene products
13. List and describe 4 complementary approaches used to map the human genome
14. Explain how RFLP analysis and PCR can be applied to the Human Genome Project
15. Describe how recombinant DNA technology can have medical applications such as diagnosis of genetic disease, development of gene therapy, vaccine production, and development of pharmaceutical products
16. Describe how gene manipulation has practical applications for agriculture
17. Describe how plant genes can be manipulated using the Ti plasmid carried by Agrobacterium as a vector
18. Explain how foreign DNA may be transferred into monocotyledonous plants
19. Describe how recombinant DNA studies and the biotechnology industry are regulated with regards to safety and policy matters

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Chapter 21

1. Distinguish between the patterns of morphogenesis in plants and animals
2. List the animals used as models of developmental biology research and provide a rationale for their choice
3. Describe how genomic equivalence was determined for plants and animals
4. Describe what kinds of changes occur to the genome during differentiation
5. Describe the general process by which Dolly was cloned
6. Describe the molecular basis of determination
7. Describe the 2 sources of information that instruct a cell to express genes at the appropriate time
8. Describe how Drosophila were used to explain basic aspects of pattern formation (axis formation and segmentation)
9. Describe how homeotic genes serve to identify parts of the developing organism
10. Provide evidence of the conservation of homeobox sequences
11. Describe how the study of nematodes contributed to the general understanding of embryonic induction
12. Describe how apotosis functions in normal and abnormal development
13. Describe how the study of tomatoes has contributed to the understanding of flower development
14. Describe how the study of Arabidopsis has contributed to the understanding of organ identity in plants

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