AP Biology Chapters 18-21 Homework Due Chapter 18: The Genetics of Viruses and Bacteria

1. Describe some of the main contributors and what they did to enhance we know about bacteria and viruses such as Mayer, Ivanowsky, Beijerinck, etc.

2. Draw and label a generic version of a virus, labeling the main structural components.

3. Using figure 18.7 compare and contrast the lytic and lysogenic cycles of phages – ie. What occurs in each, what types of viruses display these types of life cycles, etc.

4. Describe the reproductive cycle of HIV, a retrovirus (refer to figure 18.10). How does this type of reproduction compare to the lytic and lysogenic cycles?

5. Is it believed that viruses evolved before or after the first cells appeared and what evidence is used to support the idea?

6. What are vaccines?

7. What are the three processes that contribute to the emergence of viral diseases?

8. Explain what prions and viroids are. What do they infect, how do they do it, etc.

9. Explain what transduction, transformation and conjugation are and how they each contribute to genetic recombination and gene transfer within bacteria.

10. What are R plasmids and why are these problems to humans? How does this relate to natural selection?

11. Compare and contrast the trp and lac operons. We stated in the beginning of the year that negative feedback has an on/off switch and positive feedback can only amplify the response – how does this statement connect with negative and positive gene regulation?

Chapter 19: Eukaryotic Genomes: Organization, Regulation and Evolution

1. Describe the levels of chromosome packaging (fig. 19-2) within the cell. How does this dense packaging of DNA prevent gene expression? What is the difference between heterochromatin and euchromatin? Which is transcribed?

2. What effect do the following have on gene expression? a. Histone acetylation b. Histone deacteylation c. DNA methylation – (How does methylation relate to genomic imprinting?)

3. How do the following control elements assist in regulation?

a. Transcription factors b. Enhancers c. Activators d. Repressors

4. What role do microRNA’s play in post-transcriptional regulation?

5. Describe how all of the previous information relates to figure 19.3.

6. What is RNA interference?

7. Explain the role of ubiquitin in protein degredation.

8. Using Figure 19.19, what processes are thought to have led to the evolution of the globin gene families?

9. What are transposable elements and how do they contribute to the evolution of the genome?

10. Compare and Contrast the types of genes associated with cancer – proto-oncogenes, oncogenes, tumor-suppressor genes. What is p53 and it’s associated role with cancer development?

Chapter 20: DNA Technology and Genomics