BCH5413 EXAM 3 COMPREHENSIVE TEST
PAPER 2026 QUESTIONS AND CORRECT
ANSWERS GRADED A+
●● endogenous factors that cause DNA damage.
Answer: error in replication
bully addict formation
oxidation
alkylation
hydrolysis
●● exogenous factors that cause DNA damage.
Answer: UV, chemicals, x-rays, ionizing radiation
●● emethanesulfate (EMS).
Answer: DNA alkylation medicine for cancer
●● GC base pairing when guanine is exposed to EMS.
Answer: guanine to 06-ethylguanine and bins to thymine
●● EMS as a cancer treatment.
,Answer: interferes with transcriptional and DNA replication
●● alkylation event that does not change base pairing.
Answer: attacks phosphodiester bond
●● endogenous sources of oxidative stress.
Answer: respiration, stress
●● exogenous sources of oxidative stress.
Answer: smoking, alcohol, pollution, water, pesticides, medications,
food (meat)
●● Result of oxidative damage.
Answer: guanine oxidation
-biomarker of oxidative stress
-mutagenic
●● Hoogsteen base pairing.
Answer: - Occurs when one base is in the syn conformation.
-G-A base pair
●● UV-A damage.
, Answer: free radicals
●● UV-B damage.
Answer: pyrimidine dimers
●● Gamma and X-ray damage.
Answer: ss or ds DNA break, altered bases (oxidized)
●● ionizing radiation.
Answer: radiation w/enough energy to free electrons from atoms
forming ions, may cause cancer (ex. gamma, X-rays, UV). Ionizes
molecules around DNA ( water) to form highly reactive free radicals that
attack DNA backbone
●● oxidative stress, alkylating agents effect on DNA.
Answer: Base modification: alkylation, methylation, oxidation
●● polycyclic aromatic hydrocarbons effect on DNA.
Answer: adduct intercalation between bases
●● spontaneous events effect on DNA.
Answer: depyrimidation, depurination, backbone modification, base
modifications
PAPER 2026 QUESTIONS AND CORRECT
ANSWERS GRADED A+
●● endogenous factors that cause DNA damage.
Answer: error in replication
bully addict formation
oxidation
alkylation
hydrolysis
●● exogenous factors that cause DNA damage.
Answer: UV, chemicals, x-rays, ionizing radiation
●● emethanesulfate (EMS).
Answer: DNA alkylation medicine for cancer
●● GC base pairing when guanine is exposed to EMS.
Answer: guanine to 06-ethylguanine and bins to thymine
●● EMS as a cancer treatment.
,Answer: interferes with transcriptional and DNA replication
●● alkylation event that does not change base pairing.
Answer: attacks phosphodiester bond
●● endogenous sources of oxidative stress.
Answer: respiration, stress
●● exogenous sources of oxidative stress.
Answer: smoking, alcohol, pollution, water, pesticides, medications,
food (meat)
●● Result of oxidative damage.
Answer: guanine oxidation
-biomarker of oxidative stress
-mutagenic
●● Hoogsteen base pairing.
Answer: - Occurs when one base is in the syn conformation.
-G-A base pair
●● UV-A damage.
, Answer: free radicals
●● UV-B damage.
Answer: pyrimidine dimers
●● Gamma and X-ray damage.
Answer: ss or ds DNA break, altered bases (oxidized)
●● ionizing radiation.
Answer: radiation w/enough energy to free electrons from atoms
forming ions, may cause cancer (ex. gamma, X-rays, UV). Ionizes
molecules around DNA ( water) to form highly reactive free radicals that
attack DNA backbone
●● oxidative stress, alkylating agents effect on DNA.
Answer: Base modification: alkylation, methylation, oxidation
●● polycyclic aromatic hydrocarbons effect on DNA.
Answer: adduct intercalation between bases
●● spontaneous events effect on DNA.
Answer: depyrimidation, depurination, backbone modification, base
modifications
