Question

Answer all the listed questions. Provided reasoning for the correct answer. Provide reasoning for incorrect answers as well.

I will thumbs you down if you do follow the above instructions completely !!!!

17) Which if the following is a true difference between an intercalating agent and an adduct- forming agent?

a) Intercalating agents do not covalently bond with the DNA molecule.

b) Adduct forming agents interact electrostatically by wedging in between bases of a DNA molecule.

c) DNA damage from bulky adducts can only be repaired by base excision repair.

d) Ethidium bromide is considered a bulky adduct.

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19) Which of the following is not generally associated with oxidative DNA damage?

a) build-up of wastes such as reactive oxygen species.

b) DNA alkylation of bases

c) breakage if phosphodiester bonds

d) deletions and translocations

Answer 1

17) The correct answer will be

a) Intercalating agents do not covalently bond with the DNA molecule. The type of bonding is the main difference between intercalating (electrostatic bonding) and adduct forming adducts (covalent bonding).

(b) is not correct because adduct forming agents interacts through covalent bonding.

(c) is incorrect as such damage are repaired by nucleotide excision repair.

(d) is incorrect as ethidium bromide is an intercalating agent.

19) The correct option will be

b) DNA alkylation of bases. This is caused by alkylation agents.

(a) is correct statement since reactive oxygen species such as superoxide, hydrogen peroxide and hydroxyl free radicals are involved.

(c) oxidative damage can lead to strand break, i.e. phosphodiester bond breaking.

(d) deletions and translocations may arise as a result of oxidative DNA damage if they are not repaired.