Some bacteria have a higher incidence rate of thymine dimer mutations following exposure to UV light than others. What might be going on here to lead to this outcome?
A) They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria, leading to more possible dimers being formed.
B) They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria, leading to more possible dimers being formed AND they may have a stronger expression of photoreactivation enzymes, leading to formation of more thymine dimers.
C) They may simply have a higher proportion of T nucleotides next to each other in their DNA than other bacteria, leading to more possible dimers being formed AND they may have a weaker expression of photoreactivation enzymes, leading to formation of more thymine dimers.
D) They may have a stronger expression of photoreactivation enzymes, leading to more thymine dimers being formed and retained.
E) They may have a weaker expression of photoreactivation enzymes, leading to more thymine dimers being formed and retained.

Question

Some bacteria have a higher incidence rate of thymine dimer mutations following exposure to UV light than others. What might be going on here to lead to this outcome?
A) They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria, leading to more possible dimers being formed.
B) They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria, leading to more possible dimers being formed AND they may have a stronger expression of photoreactivation enzymes, leading to formation of more thymine dimers.
C) They may simply have a higher proportion of T nucleotides next to each other in their DNA than other bacteria, leading to more possible dimers being formed AND they may have a weaker expression of photoreactivation enzymes, leading to formation of more thymine dimers.
D) They may have a stronger expression of photoreactivation enzymes, leading to more thymine dimers being formed and retained.
E) They may have a weaker expression of photoreactivation enzymes, leading to more thymine dimers being formed and retained.

Quizplus · Accepted Answer

Thymine dimers are formed when two adjacent thymine nucleotides bond together after being damaged by UV light. A higher incidence rate of these mutations could be due to a higher proportion of adjacent thymine nucleotides (making dimer formation more likely) and a weaker expression of photoreactivation enzymes, which are responsible for repairing such damage. Stronger expression of these enzymes would lead to fewer, not more, thymine dimers being retained.

Some Bacteria Have a Higher Incidence Rate of Thymine Dimer