Question

Genetics Question

How could a multiple choice question determine whether students are clear about the differences or similarities between replication and transcription?

Write a multiple choice question that gets at similarities or differences between DNA replication and transcription. In your responses to other students questions you could choose to make it more straightforward, or suggest a way to make it more challenging, or perhaps you could show how a small wording change would lead to a different answer.

Answer 1

Q1) Which of the following statement is true regarding DNA replication and Transcription?

a) Misincorporated bases can be removed only in DNA replication process and not in Transcription.

b) Misincorporated bases can be removed in both the processes.

c)Misincorporsted bases cannot be removed by both these processes.

d) Misincorporated bases can be removed only in Transcription process and not in the DNA replication process.

The correct option is "b" because DNA polymerases have 3' to 5' exonuclease activity to remove incorrect or misincorporated bases which have been added during errors in DNA replication.But RNA Polymerases can also remove incorrect bases by Hydrolytic editing (RNA Polymerase move 1 or 2 nucleotides backwards to cleave wrong base) and Pyrophosphohydrolytic editing (RNA polymerase adds pyrophosphate group and remove incorrect base).

Students are most likely to choose Answer "a" because they are well aware of DNA polymerases having 3' - 5' exonuclease activity but they should also know that RNA polymerases also has inherent RNAse activity in them.