Biol 207 Midterm 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Mutation - CORRECT ANSWER - a permanent change in genetic material (doesn't
necessarily change phenotype)
Base substitutions - CORRECT ANSWER - single base pair change; genotypic mutation
Transition - CORRECT ANSWER - substitute purine for purine (A for G) or pyrimidine
for pyrimidine (C for G); genotypic mutation
Transversion - CORRECT ANSWER - substitute purine for a pyrimidine or vice versa;
genotypic mutation
Insertion/deletion (indel) - CORRECT ANSWER - insertion or deletion of less than 5
nucleotides that may or may not cause frameshift mutations; genotypic mutation
Silent mutation - CORRECT ANSWER - doesn't change AA; phenotypic mutation
Missense mutation - CORRECT ANSWER - codes for wrong AA; phenotypic mutation
Nonsense mutation - CORRECT ANSWER - no AA coded; phenotypic mutation
Exonuclease - CORRECT ANSWER - digests nucleic acids from end and helps DNA
polymerase correct mistakes
Slippage - CORRECT ANSWER - a strand of DNA slips and doesn't realign properly;
occurs in repetitive sequences
, Depurination - CORRECT ANSWER - loss of a purine base off of a nucleotide
Deamination - CORRECT ANSWER - loss of a NH group
Oxidative damage - CORRECT ANSWER - oxidizing a group so it no longer participates
in H-bonds with other bases and the nucleotide binds with a different base
Tautomerization - CORRECT ANSWER - random and rapid isomers of a nucleotide that
causes transitions
Stabilized mutant - CORRECT ANSWER - no longer detectable by repair machinery
Ames test - CORRECT ANSWER - test to identify a mutagen that looks for revertants
Revertants - CORRECT ANSWER - has second mutation that creates wildtype phenotype
Base analogs - CORRECT ANSWER - look like a base to DNA pol, but have incorrect
base pairing (used in chemotherapy)
Lesion - CORRECT ANSWER - damaged base
Photolyase - CORRECT ANSWER - cleaves bond between pyrimidines
Addition of alkyl or methyl groups - CORRECT ANSWER - causes transitions because H
base pairing is interfered (binds with different base pair)
Intercalating agents - CORRECT ANSWER - fit inside the stacked bases and causes
distortion in helix; results in insertions during replication
Exam Questions and CORRECT Answers
Mutation - CORRECT ANSWER - a permanent change in genetic material (doesn't
necessarily change phenotype)
Base substitutions - CORRECT ANSWER - single base pair change; genotypic mutation
Transition - CORRECT ANSWER - substitute purine for purine (A for G) or pyrimidine
for pyrimidine (C for G); genotypic mutation
Transversion - CORRECT ANSWER - substitute purine for a pyrimidine or vice versa;
genotypic mutation
Insertion/deletion (indel) - CORRECT ANSWER - insertion or deletion of less than 5
nucleotides that may or may not cause frameshift mutations; genotypic mutation
Silent mutation - CORRECT ANSWER - doesn't change AA; phenotypic mutation
Missense mutation - CORRECT ANSWER - codes for wrong AA; phenotypic mutation
Nonsense mutation - CORRECT ANSWER - no AA coded; phenotypic mutation
Exonuclease - CORRECT ANSWER - digests nucleic acids from end and helps DNA
polymerase correct mistakes
Slippage - CORRECT ANSWER - a strand of DNA slips and doesn't realign properly;
occurs in repetitive sequences
, Depurination - CORRECT ANSWER - loss of a purine base off of a nucleotide
Deamination - CORRECT ANSWER - loss of a NH group
Oxidative damage - CORRECT ANSWER - oxidizing a group so it no longer participates
in H-bonds with other bases and the nucleotide binds with a different base
Tautomerization - CORRECT ANSWER - random and rapid isomers of a nucleotide that
causes transitions
Stabilized mutant - CORRECT ANSWER - no longer detectable by repair machinery
Ames test - CORRECT ANSWER - test to identify a mutagen that looks for revertants
Revertants - CORRECT ANSWER - has second mutation that creates wildtype phenotype
Base analogs - CORRECT ANSWER - look like a base to DNA pol, but have incorrect
base pairing (used in chemotherapy)
Lesion - CORRECT ANSWER - damaged base
Photolyase - CORRECT ANSWER - cleaves bond between pyrimidines
Addition of alkyl or methyl groups - CORRECT ANSWER - causes transitions because H
base pairing is interfered (binds with different base pair)
Intercalating agents - CORRECT ANSWER - fit inside the stacked bases and causes
distortion in helix; results in insertions during replication
