#4 TED-Ed What Happens When Your DNA is Damaged? Quiz

How many DNA errors occur in the cells of the human body per day?

• Tens of thousands
• Hundreds of millions
• Trillions
• Quintillions

What is the primary cause of damage to DNA in cells?

• UV radiation
• Hydrogen peroxide
• Replication errors
• All of the above

Which enzyme is responsible for correcting base mismatches during DNA replication?

• DNA polymerase
• DNA ligase
• Endonuclease
• Topoisomerase

What is the process called when an enzyme removes a damaged nucleotide and replaces it with the correct one?

• Mismatch repair
• Base excision repair
• Nucleotide excision repair
• Non-homologous end joining

Which DNA repair pathway uses an undamaged section as a template to fix double-strand breaks?

• Homologous recombination
• Non-homologous end joining
• Mismatch repair
• Base excision repair

Match the following

• ligase

• works in 5' to 3' direction replicating DNA

• Okazaki fragments

• sections of lagging DNA strand

• leading DNA strand

• continuously replicated in 5' to 3' direction

• lagging DNA strand

• joins DNA strands

• DNA polymerase

• replicated in sections in 3' to 5' direction

Match the following molecules to their function:

• an enzyme that adds new nucleotides to the exposed strands, creating new DNA

• Ligase

• process using old strands to build new

• semi-conservative replication

• an enzyme that adds new nucleotides to the exposed strands, creating an RNA copy

• Helicase

• enzyme checks for errors and glues

• RNA Polymerase

• an enzyme that breaks the bonds that hold the double helix together

• DNA Polymerase

Original DNA: CAGAAT

Mutated DNA: CAGAT = ​ (a)  

Mutated DNA: CAGCAAT = ​ (b)  

Mutated DNA: CAGTAT = ​ (c)  

• Deletion
• Insertion
• Substitution

Which two are Frameshift Mutations?

Label the parts!

c

d

e

f

a

b

RNA primer

Primase

Replication fork

single stranded binding protein

Topoisomerase

Helicase