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Biol 207 Midterm 2 Questions with Answers (100%
Correct Answers)
Mutation Answer: a permanent change in genetic material (doesn't
necessarily change phenotype)
Base substitutions Answer: single base pair change; genotypic mutation
Transition Answer: substitute purine for purine (A for G) or pyrimidine
for pyrimidine (C for G); genotypic mutation
Transversion Answer: substitute purine for a pyrimidine or vice versa;
genotypic mutation
Insertion/deletion (indel) Answer: insertion or deletion of less than 5
nucleotides that may or may not cause frameshift mutations; genotypic
mutation
Silent mutation Answer: doesn't change AA; phenotypic mutation
Missense mutation Answer: codes for wrong AA; phenotypic mutation
Nonsense mutation Answer: no AA coded; phenotypic mutation
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Exonuclease Answer: digests nucleic acids from end and helps DNA
polymerase correct mistakes
Slippage Answer: a strand of DNA slips and doesn't realign properly;
occurs in repetitive sequences
Depurination Answer: loss of a purine base off of a nucleotide
Deamination Answer: loss of a NH group
Oxidative damage Answer: oxidizing a group so it no longer
participates in H-bonds with other bases and the nucleotide binds with
a different base
Tautomerization Answer: random and rapid isomers of a nucleotide
that causes transitions
Stabilized mutant Answer: no longer detectable by repair machinery
Ames test Answer: test to identify a mutagen that looks for revertants
Revertants Answer: has second mutation that creates wildtype
phenotype
© 2025 All rights reserved
Biol 207 Midterm 2 Questions with Answers (100%
Correct Answers)
Mutation Answer: a permanent change in genetic material (doesn't
necessarily change phenotype)
Base substitutions Answer: single base pair change; genotypic mutation
Transition Answer: substitute purine for purine (A for G) or pyrimidine
for pyrimidine (C for G); genotypic mutation
Transversion Answer: substitute purine for a pyrimidine or vice versa;
genotypic mutation
Insertion/deletion (indel) Answer: insertion or deletion of less than 5
nucleotides that may or may not cause frameshift mutations; genotypic
mutation
Silent mutation Answer: doesn't change AA; phenotypic mutation
Missense mutation Answer: codes for wrong AA; phenotypic mutation
Nonsense mutation Answer: no AA coded; phenotypic mutation
© 2025 All rights reserved
, 2
Exonuclease Answer: digests nucleic acids from end and helps DNA
polymerase correct mistakes
Slippage Answer: a strand of DNA slips and doesn't realign properly;
occurs in repetitive sequences
Depurination Answer: loss of a purine base off of a nucleotide
Deamination Answer: loss of a NH group
Oxidative damage Answer: oxidizing a group so it no longer
participates in H-bonds with other bases and the nucleotide binds with
a different base
Tautomerization Answer: random and rapid isomers of a nucleotide
that causes transitions
Stabilized mutant Answer: no longer detectable by repair machinery
Ames test Answer: test to identify a mutagen that looks for revertants
Revertants Answer: has second mutation that creates wildtype
phenotype
© 2025 All rights reserved
