TED-Ed: What happens when your DNA is damaged? - Monica Menesini

DNA in our cells is damaged thousands of times daily, leading to potential errors that can cause serious issues like cancer. Fortunately, cells have repair mechanisms involving specialized enzymes to fix these errors. Base mismatches are corrected by DNA polymerase and mismatch repair systems. Chemical changes from environmental and natural sources are addressed by specific and general repair pathways, such as base excision repair. Radiation causes more severe damage, requiring complex processes like nucleotide excision repair and homologous recombination. While some DNA changes can be beneficial for evolution, most are harmful, and defects in repair mechanisms are linked to aging and cancer.

What is the role of DNA polymerase during DNA replication?

• To create new DNA strands from scratch

• To remove entire DNA strands

• To pair nucleotides with their correct partners

• To break down damaged DNA

Which process is used to fix a single damaged base in DNA?

• Homologous recombination

• Nucleotide excision repair

• Base excision repair

• Mismatch repair

What type of damage does UV light cause to DNA?

• Complete DNA strand removal

• Adjacent nucleotides sticking together

• Base mismatches

• Severing of DNA strands

How does homologous recombination repair double strand breaks?

• By using a similar DNA section as a template

• By trimming and fusing broken ends

• By creating new DNA strands

• By removing damaged bases

What is a potential positive outcome of DNA mutations?

• Cell death

• Species evolution

• Increased risk of cancer

• Premature aging