Self assessment Lecture 35 Key Replication Mutation and Repair Self Assessment Lecture 35 1 Silent mutations a Can occur in the coding region b Can occur in the intron c Can occur in the 5 and in the 3 non coding regions d All the above note why can a mutation in the coding region not result in a phenotypic change 2 A change in only one amino acid is called a point mutation 3 A mutation which results in a change from A to T transition transversion 4 A mutation which results in a change from A to G transition transversion 5 In a Missense mutation The mutation results in a change of amino acid encoded 6 In a Non sense mutation The mutation results in a stop codon and so a truncation 7 If a mutation results the insertion or deletion of only one nucleotide in the coding region it will generally have a much lesser effect on the phenotype than if the mutation is a deletion or insertion of 15 deoxynucleotides TF 8 Please name two chemicals that were discussed which intercalate into the DNA a Acridine Orange b Ethidium bromide 9 Intercalators in Q10 generally cause what type of mutation frame shift 10 If a in the figure right is the normal chromosome please identify b and c a inversion b translocation 11 Both b and c arise from a DNA Single strand break b DNA Double strand break 12 Huntington s disease is a defect in what protein Huntingtin 13 Please describe the type of mutation that results in a b c Huntington s disease insertion of a tridNTP repeat that results in expansion of a polyglutamine tract in the huntingtin protein 14 Please describe anticipation with as it pertains to Huntington s disease in anticipation the severity increases and age of symptom onset decreases 15 DNA bases are predominantly in the enol keto configuration but this process can cause a shift in double bond location to produce the enol keto form tautomerization 16 Alfatoxin s a compound found in peanut mold and is itself a potent carcinogen TF 17 During mismatch repair how is the newly synthesized strand identified from the parent template strand Only the old strand is methylated Self assessment Lecture 35 Key Replication Mutation and Repair 18 Please place the following in correct order for mismatch repair in E coli c a d e b a MulL b DNA Pol III c MutS d MutH e Exonuclease I 19 Humans can repair thymine dimers through use of a the enzymeDNA photolyase b nucleotide excision repair c both a and b are used 20 What is an AP site and what enzyme creates it apurinic apyrimidinic site created through action of glycosylase which cleaves off the base 21 DNA Recombination does which of the following a Repairs DNA b Increases diversity in offspring c Generates antibody diversity d Introduces new genes e All but c f a d are all true 22 Please put the event of homologous recombination in order d f a c b e a 3 Strand invasion b Branch migration c Ligation of the 3 end of one homologous strand to it s homolog in the other double strand d Chromosome synapsis e Duplex resolution to form two new double strands of DNA f SS nicking this is cleaving one strand of a duplex DNA 23 How does Rec A participate in recombination in E coli Rec A coats the invading strand and stabilizes its interaction with the duplex DNA to promote strand invasion Please be prepared to explain the functions of Ruv A B and C also
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