Download Chapter 13-15 Essential Knowledge

Chapter 13, 14 & 15 Essential Knowledge
Write a detailed response to each of the following pieces of information. If numbers are
given in parentheses, they refer to the pages of your text book.
Main Concept: DNA & sometimes RNA is the primary source of heritable information. &
Gene regulation results in differential gene expression, leading to cell specialization.
1. Describe how the following experiments contributed to our knowledge of DNA as the
genetic material:
a. Watson & Crick, Wilson, Franklin
b. Avery-MacLeod-McCarty Experiment
c. Hershey-Chase Experiment
2. Why is it important that DNA replication is semi-conservative?
3. How does DNA replication differ on the leading and lagging strands? Include the
following in your answer: DNA Polymerase I & III, ligase, topoisomerase, and Okazaki
fragments.
4. Describe the role of each of the following in gene expression:
a. DNA
b. mRNA
c. tRNA
d. rRNA
5. List the differences between RNA and DNA.
6. How does RNA polymerase make RNA? What is meant by the 3’ to 5’ direction?
7. Describe the following RNA post-transcriptional modifications made in eukaryotic cells
a. Addition of Poly-A tail
b. Addition of a GTP cap
c. Excision of introns (why doesn’t this happen in prokaryotes?)
8. Describe a genetic mutation and explain when it is beneficial and when it is harmful.
9. How do external factors (radiation, reactive chemicals) cause DNA mutations?
10. Describe the role of promoter, terminators and enhancers in gene regulation.
11. What are regulatory genes and regulatory proteins?
12. Describe Negative gene regulation in both the lac and trp operons.
13. Describe positive gene regulation in the lac operon.
14. How is the development of an organism regulated by:
a. Cell differentiation as a result of gene expression for tissue specific proteins.
b. Induction of transcription factors during development in sequential gene
expression.
15. What is the role of microRNAs in genetic regulation of the development of organisms
and the control of their cellular functions during development?
16. How do environmental stimuli affect gene expression (think epigentics)?
17. Operons:
a. How does an inducer turn on the expression of a gene?
b. How does a repressor inhibit the expression of a gene?
c. How do inducers and repressors interact with regulatory proteins and gene
sequences?
d. How does a regulatory protein inhibit gene expression (think negative control).
e. How does a regulatory protein stimulate gene expression (think positive control).
f. Why are the ribosomal genes continually expressed?
g. How do transcription factors interact with specific DNA sequences?
h. Describe how the combination of transcription factors and the regulatory regions
of genes determine how much (if any) of the gene product will be produced.
i. Describe a transcription factor that acts as an
i. Activator
ii. Repressor