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Biol 211, Fall 2008
Exam #4
Name ____________________
Section 1. Questions in this section can be answered with one or a few words.
For the following definitions, provide the correct term.
1. Small proteins that are involved in chromatin packing. (1 pt)
2. Enzyme that transcribes RNA template into DNA in retroviruses. (1 pt)
3. A sequence of 3 nitrogenous bases in mRNA that code for a specific amino acid. (1 pt)
4. Mis-folded protein that causes degenerative brain diseases. (1 pt)
5. The progressive restriction of the developmental potential of a cell to only one specific fate. (1 pt)
6. Sequence of nucleotides in a bacteria’s DNA to which an active repressor can attach that prevents
transcription of a cluster of genes. (1 pt)
7. Any observable trait in an individual. (1 pt)
Answer the following questions.
8. What do homeotic genes control? (1 pt)
9. What effect does microRNAs (miRNAs) have on messenger RNA (mRNA)? (1 pt)
10. Transcribe the following single strand of DNA into a strand of RNA: ATCCGCTAAGTCAG (1 pt)
11. What is the function of a splicesome? (1 pt)
12. Briefly describe one way that expression of a gene can be regulated after the pre-mRNA (primary
transcript) has been made? (1 pt)
13. Can genes located within heterochromatin regions be transcribed (Y/N)?(1 pt)
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Biol 211, Fall 2008
Exam #4
Name ____________________
14. What is one way we get emerging viruses (appearance of new viruses)? (1 pt)
15. What are the components of an operon? (1 pt)
Section 2. Short Answer.
16. Provide a concise definition for each that will clearly distinguish between the following pairs of
terms. Be sure to include how the two terms are related to one another. (2 pts each):
a) lytic cycle / lysogenic cycle
b) repressible operon / inducible operon
c) transcription / translation
Answer the following questions.
17. How do cyctoplasmic determinants influence cell differentiation?
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(3 pts)
Biol 211, Fall 2008
Exam #4
Name ____________________
18. Describe how the structure of tRNA allows it to change the nucleic acid “language” of mRNA into
amino acid “language”. (3 pts)
19. Why is the phrase “one gene, one polypeptide” inaccurate? (2 pts)
20. What would happen in the lactose metabolic pathway of a bacteria grown in a petri dish where
glucose concentrations are low and there is no allolactose present? Explain why. (3 pts)
21. Describe the early experiment that determined that bacteria was not the cause of tobacco mosaic
disease. (2 pts)
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Biol 211, Fall 2008
Exam #4
Name ____________________
22. Why do we have to get new flu vaccine shots every year? ( 2 pts)
23. Describe two ways that adding chemical groups to chromatin affects whether or not a gene gets
expressed. (3 pts)
24. What is one possible effect on a cell if a mutation occurred in the p53 gene? Be specific. (3 pts)
25. How is it possible that a mutation causing a base-pair substitution can cause no change in the
expression of the gene? ( 3pts)
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Biol 211, Fall 2008
Exam #4
Name ____________________
Bonus Question (2pts)
Answer only one of the question below.
1. Linked genes violate Mendel’s Law of Independent Assortment (LIA). Under what circumstances
might it appear that Mendel’s LIA holds true for linked genes?
2 What is the role of PEP Carboxylase in photosynthesis and why is it important?
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