Practice Exam 3 Key

Practice Exam 3 Key - B172 Exam 3 11/19/07 Name: _ 1) Which...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
B172 Exam 3 11/19/07 Name: ___________________________________ 1) Which is an accurate statement regarding the genetic code? A. AUG is a terminating codon. B. There can be more than one codon for a particular amino acid. C. The code is ambiguous in that the same codon can code for two or more amino acids. D. There are 44 stop codons because there are only 20 amino acids. 2) Which of the following is critical for transcription initiation? A. promoter B. 3’ UTR C. initiator tRNA D. origin of replication E. start codon 3) A eukaryotic protein is 300 amino acids long. What is the minimum size of the coding sequences for the corresponding gene? (bp = basepair) A. 1800 bp B. 900 bp C. 600 bp D. 300 bp E. 100 bp 4) In eukaryotes, several events occur between transcription and translation. Which of the following events does NOT occur during this period? A. unwinding of the RNA helix B. transport of the mRNA to the cytosol C. RNA splicing D. addition of a poly-A tail to the RNA E. addition of a cap to the RNA 5) When moving a gene from a eukaryotic system to a prokaryotic system, which of the following does NOT need to be changed? A. translation initiation signals B. introns C. transcription termination sites D. transcription start sites E. coding sequence 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
B172 Exam 3 11/19/07 Name: ___________________________________ 9. How will a mutation that greatly decreases the amount of cAMP in E. coli affect the lac Operon? a. The LacI repressor will not bind lactose. b. Lactose will be efficiently metabolized when there is high glucose. c. CAP will bind the CAP site. d. Lactose will not be efficiently metabolized even in the absence of glucose. 10. In a normal E. coli which of the following conditions would lead to efficient transcription of the lacZ and lacY genes? a. Low glucose and low lactose. b. Low glucose and high lactose. c. High glucose and low lactose. d. High glucose and high lactose. 11. You perform footprinting analysis of the lac Operon DNA from a strain of E. coli with the LacI Repressor protein and get the following result. What does the gap in the ladder of DNA fragments represent? a. the CAP binding site b. lacI gene c. lacZ gene d. the operator sequence 2
Background image of page 2
B172 Exam 3 11/19/07 Name: ___________________________________ 12. EcoR1 is a restriction enzyme. EcoR1 sites flank gene X and flank gene Y. You digest genomic DNA from a liver (eukaryotic) cell with DNase (D) or not digest (C), expose the DNA to low salt conditions to decondense chromatin, cut the DNA with EcoR1 and analyze the DNA fragments by Southern analysis for genes X and Y. Below are the Southern blots.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 9

Practice Exam 3 Key - B172 Exam 3 11/19/07 Name: _ 1) Which...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online