BIO 305 EVALUATION 2026 EXAMS QUESTIONS AND
ANSWERS SURE A+
✔✔different types of mutations - ✔✔-substitution
-insertion
-deletion
-frame shift
✔✔Mutation Repair - ✔✔1. *DNA polymerase* - proofreads nucleotides during DNA
replication
2. *Mismatch repair* - locates and repairs mismatched nitrogen bases that were not
repaired by DNA polymerase
3. *Light repair* - for UV light damage
4. *Excision repair* - locates and repairs incorrect sequence by removing a segment of
the DNA and then adding the correct nucleotides
✔✔What causes mutations? - ✔✔Radiation, Chemicals, Errors as a gene is being
copied
-exposure to a mutagen
✔✔Exposure to mutagens - ✔✔Some mutagen exposure is unintentional
- Workplace
- Industrial accidents fukushima
, - Chernobyl
- Medical treatments
- Weapons
- Natural sources
- Cosmic rays, sunlight, earth's crust
✔✔3 types of DNA repair - ✔✔photo reactivation repair, excision repair, mismatch
repair.
✔✔which of the following DNA sequences is most likely to mutate? Cite a reason for
your answer. a.CTGAGTCGTGACTCGTACGTCAT.
b.ATGCTCAGCTACTCAGCTACGGA.
c.ATCCTAGTCGTCGTCGTCGTCATC - ✔✔c
✔✔explain how a mutation causes sickle cell disease - ✔✔Sickle cell disease results in
an amino acid substitution that causes the red blood cell to assume a shape in places
where oxygen level is low that blocks circulation.
✔✔photoreactivation repair - ✔✔Enzymes called photolyases use light energy to break
the extra bonds in a pyrimidine dimer
Enables UV-damaged fungi to recover from exposure to sunlight
Humans do not have this type of repair
✔✔excision repair - ✔✔locates and repairs incorrect sequence by removing a segment
of the DNA and then adding the correct nucleotides
✔✔mismatch repair - ✔✔The cellular process that uses specific enzymes to remove
and replace incorrectly paired nucleotides.
✔✔Repair of Mutations - ✔✔DNA polymerase proofreads the new strand against the old
strand. If errors occur in sex cells - mutation may be passed onto offspring. If errors
occur in body cells- cancer may result
✔✔conditional mutation produces - ✔✔a phenotype under particular conditions
✔✔gene expression - ✔✔The process by which information encoded in DNA directs the
synthesis of proteins or, in some cases, RNAs that are not translated into proteins and
instead function as RNAs.
✔✔Epigenetics - ✔✔the study of environmental influences on gene expression that
occur without a DNA change
ANSWERS SURE A+
✔✔different types of mutations - ✔✔-substitution
-insertion
-deletion
-frame shift
✔✔Mutation Repair - ✔✔1. *DNA polymerase* - proofreads nucleotides during DNA
replication
2. *Mismatch repair* - locates and repairs mismatched nitrogen bases that were not
repaired by DNA polymerase
3. *Light repair* - for UV light damage
4. *Excision repair* - locates and repairs incorrect sequence by removing a segment of
the DNA and then adding the correct nucleotides
✔✔What causes mutations? - ✔✔Radiation, Chemicals, Errors as a gene is being
copied
-exposure to a mutagen
✔✔Exposure to mutagens - ✔✔Some mutagen exposure is unintentional
- Workplace
- Industrial accidents fukushima
, - Chernobyl
- Medical treatments
- Weapons
- Natural sources
- Cosmic rays, sunlight, earth's crust
✔✔3 types of DNA repair - ✔✔photo reactivation repair, excision repair, mismatch
repair.
✔✔which of the following DNA sequences is most likely to mutate? Cite a reason for
your answer. a.CTGAGTCGTGACTCGTACGTCAT.
b.ATGCTCAGCTACTCAGCTACGGA.
c.ATCCTAGTCGTCGTCGTCGTCATC - ✔✔c
✔✔explain how a mutation causes sickle cell disease - ✔✔Sickle cell disease results in
an amino acid substitution that causes the red blood cell to assume a shape in places
where oxygen level is low that blocks circulation.
✔✔photoreactivation repair - ✔✔Enzymes called photolyases use light energy to break
the extra bonds in a pyrimidine dimer
Enables UV-damaged fungi to recover from exposure to sunlight
Humans do not have this type of repair
✔✔excision repair - ✔✔locates and repairs incorrect sequence by removing a segment
of the DNA and then adding the correct nucleotides
✔✔mismatch repair - ✔✔The cellular process that uses specific enzymes to remove
and replace incorrectly paired nucleotides.
✔✔Repair of Mutations - ✔✔DNA polymerase proofreads the new strand against the old
strand. If errors occur in sex cells - mutation may be passed onto offspring. If errors
occur in body cells- cancer may result
✔✔conditional mutation produces - ✔✔a phenotype under particular conditions
✔✔gene expression - ✔✔The process by which information encoded in DNA directs the
synthesis of proteins or, in some cases, RNAs that are not translated into proteins and
instead function as RNAs.
✔✔Epigenetics - ✔✔the study of environmental influences on gene expression that
occur without a DNA change
