Unformatted text preview: ut usually not identical sequences. After a gene duplication event, what
could happen to the duplicated genes over evolution? i. Our genome contains around 300 rRNA gene repeats. What is the evolutionary
advantage of having so many repeats of this gene? 3. Mobile DNA Elements
A. Name the two different classes of mobile elements and briefly list their mechanisms
of transposition. B. When transposition occurs into different regions of a protein-coding gene, it could
potentially lead to various problems for the cell. For which of the following situations
would transposition likely alter the amino acid sequence of the protein produced by the
affected gene? Insertion into the...
i. Coding region:
C. Bacterial DNA Transposons encode the enzyme, transposase, which catalyzes DNA
transposition. What two types of enzymatic functions does transposase serve? D. What two enzymes are required to complete the transposition event after the DNA
transposon has been inserted into the target DNA sequence?
E. Why would a mutation in a DNA transposon that prevents its transcription also
prevent its transposition? F. Retrotransposons sometimes mistakenly retrotranspose normal genes instead of the
desired retrotransposon regions, which can result in creation of pseudogenes. Why is
this mistake normally associated with loss of the normal gene’s introns? 4. PCR (Polymerase Chain Reaction)
A. Why is it necessary to add two primers to carry out a PCR reaction? B. What would the product be, and how much product would you get, if only one primer
was added? C. Why do we use DNA polymerases isolated from organisms that live at very high
temperatures for PCR? D. Briefly describe what happens during one thermal cycle of PCR. 5. DNA Fingerprinting
A. The types of DNA sequence that are the basis of DNA fingerprinting are
______________ and __________.
B. A PCR is performed on DNA with several different _________ pairs and the
fragments are separated...
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