Practice Problems Review Session 11 16 23 Transcription Initiation Termination RNA processing Block intron removal Cause exon skipping Translation Initiation Elongation Termination RNA size Bigger Smaller No change Protein size Bigger Smaller No change Transcription Initiation Regulatory region TATA box Enhancers TF binding sites Termination Poly A signal sequence RNA processing Block Removal Block Delete Donor or Branch site Exon Skipping Block Delete Acceptor site Translation Initiation Ribosome Binding Sequences at 5 end of mRNA Start of Translation AUG start codon Elongation Open reading frame shaded region Stop codons block elongation nonsense mutations frameshifts Termination Stop Codon Release Factor Transcription Initiation Termination RNA processing Block intron removal Cause exon skipping Translation Initiation Elongation Termination RNA size Bigger Smaller No change Protein size Bigger Smaller No change Problem 8 21 Which of the following are true 8 A deletion of 8 bases at position A could cause this gene to be expressed in cells that normally do not express it 9 The 5 end of the primary transcript has a sequence that complements the DNA template strand between positions B and C 10 Insertion of 5 bases at position C could cause a frameshift mutation 11 There is a start codon at position D 12 Amino acids translated from coding sequences at position E can cause the ribosome to dock with the ER membrane 13 There could be a in frame stop codon in the open reading frame at position F which is the end of the exon 14 Transcription of Exon 2 starts about 26 base pairs from a TATA box at position G 15 There can never be a methionine ATG codon at position H 16 snRNPs bind to the primary transcript at position I 17 There can be any codons except stop codons at position J which is the start of Exon 3 18 The ribosome releases the mRNA at position K 19 Deletion of 10 bases at position L could produce a larger primary transcript 20 The ribosome releases the mRNA at position M 21 Sequences at position N are transcribed as part of this gene but are not translated Problem 222 29 Which of the following are true regarding the gene at the top of the page 22 Insertion of 30 bases at position C could produce gel set A 23 Deletion of 10 bases at position H could produce gel set B 24 Binding of a protein to position I could produce gel set C 25 Insertion of 30 bases at position H could produce gel set D 26 A nonsense mutation at position H could produce gel set E 27 A deletion of 10 bases at position K could produce gel set F 28 A change in the DNA sequence at position B could produce gel set G 29 Insertion of 50 bases into Intron 2 could produce gel set H Problem 22 29 Which of the following are true regarding the gene at the top of the page 30 Deleting sequences between positions A and B could produce gel set G 31 A point mutation between positions E and F could produce gel set B 32 Binding of a protein to position I could produce gel set C 33 Deletion of sequences between positions F and G could produce gel set C 34 Deletion of 10 bases from position H could produce gel set E 35 Deletion of a single base from position K could produce gel set A 36 Deletion of 50 bases from position N could produce gel set H 37 Insertion of 50 bases into position C could produce gel set H CDKI RNA Binding Protein ATG Exon1 CDKI gene TAA Exon2 ATG TAA Exon1 Exon2 Exon3 Exon3 TAG Larger mRNA containing all 3 exons ATG TAA TAG Small non functional CDKI protein RNA binding protein CDKI RNA Binding Protein ATG Exon1 Normal CDKI gene TAA Exon2 ATG Exon1 TAA Exon3 ATG TAG Exon3 TAG Smaller mRNA containing exons 1 3 Larger functional CDKI protein When CDKI is expressed but CDKI RNA Binding Protein is not the splicing of the CDKI mRNA includes all three exons Because the reading frame in Exon 2 is very short this mRNA produces a smaller non functional CDKI protein When CDKI and CDKI RNA Binding Protein are both expressed CDKI RNA binding protein binds to the acceptor site of Intron 1 of the CDKI primary transcript and causes skipping of Exon2 Thus the CDKI mRNA only contains Exon 1 and Exon 3 The reading frame extending from Exon1 into Exon 3 is longer and encodes a larger function CDKI protein Keisha and Matt both made constructs of the CDKI gene with GFP inserted in frame in Exon 2 and RFP inserted in frame in Exon 3 Keisha s construct retains the stop codon in Exon 2 Matt s construct deletes the stop codon in Exon 2 Both constructs are subject to alternative splicing depending on the expression of RNA binding protein that blocks the Acceptor site in Intron 1 Which of the following are true about Keisha and Matt s constructs and RNA binding protein expression 1 When RNA binding protein is not expressed Keisha s construct makes cells glow green only 2 When RNA binding protein is not expressed Matt s construct makes cells glow green only 3 When RNA binding protein is expressed Keisha s construct makes cells glow red only 4 When RNA binding protein is expressed Matt s construct makes cells glow green and red 5 If cells are glowing green and red they must contain Matt s construct and RNA binding protein must not be expressed