DNA Replication and Mutation Concepts

The video tutorial introduces the concept of mutations, explaining their definition, constraints, and significance in genetics. It discusses how mutations arise during DNA replication, the role of DNA polymerase, and the mechanisms of proofreading and mismatch repair. The impact of mutations on fitness, evolution, and diseases like cancer is also covered.

What is the primary focus of the first lecture in module two?

• Cell division

• Protein synthesis

• Genetic inheritance

• Errors in DNA replication

Which of the following is NOT a requirement for a change to be considered a mutation?

• It must be structurally normal DNA

• It must be inherited by daughter DNA molecules

• It must differ from the normal DNA sequence

• It must be a change in the protein sequence

How do mutations affect species over time?

• They have no impact on evolution

• They always improve fitness

• They prevent natural selection

• They can lead to species extinction

What is the role of DNA polymerase during DNA replication?

• To replicate the DNA template strand

• To initiate cell division

• To repair damaged DNA

• To synthesize proteins

What is the function of proofreading in DNA replication?

• To terminate replication

• To initiate DNA synthesis

• To ensure proper base pairing

• To increase the error rate

What happens if DNA polymerase fails to correct a mismatch?

• The mismatch becomes a permanent mutation

• The mismatch is ignored

• The mismatch is corrected by another enzyme

• The mismatch causes immediate cell death

What is the approximate error rate of DNA replication with proofreading?

• 10^-8 errors per base pair

• 10^-9 errors per base pair

• 10^-3 errors per base pair

• 10^-5 to 10^-6 errors per base pair

What additional system helps correct errors that proofreading misses?

• Base excision repair

• Nucleotide excision repair

• Homologous recombination

• Mismatch repair

How does the mismatch repair system identify errors?

• By comparing with RNA sequences

• By measuring the length of the DNA

• By feeling the shape of the DNA

• By checking the sequence of nucleotides

What is the final error rate of DNA replication after mismatch repair?

• 10^-6 errors per base pair

• 10^-9 errors per base pair

• 10^-5 errors per base pair

• 10^-8 errors per base pair