Mechanisms of DNA Damage and Repair

The video tutorial explores DNA damage and repair mechanisms, emphasizing the importance of DNA integrity. It covers various mutation types, including point, missense, nonsense, and frameshift mutations, and their potential effects on organisms. The tutorial also discusses causes of mutations, such as spontaneous errors and external mutagens like radiation. Finally, it highlights DNA repair mechanisms, including mismatch, nucleotide excision, and base excision repair, and the role of enzymes in maintaining genetic stability.

What is the primary role of DNA in the cell?

• To protect the cell from external damage

• To transport oxygen in the bloodstream

• To serve as a template for building proteins

• To provide energy for cellular processes

Which type of mutation involves a change in a single nucleotide?

• Large-scale mutation

• Point mutation

• Frameshift mutation

• Silent mutation

What is a silent mutation?

• A mutation that does not change the amino acid sequence

• A mutation that changes the amino acid sequence

• A mutation that causes a frameshift

• A mutation that results in a stop codon

How can a missense mutation affect a protein?

• It causes the protein to be longer than usual

• It may change the protein's shape and function

• It always results in a non-functional protein

• It has no effect on the protein

What is the result of a frameshift mutation?

• No change in the protein

• A single amino acid change

• A premature stop codon

• A silent mutation

What is a spontaneous mutation?

• A mutation caused by external factors

• A mutation that is always repaired

• A mutation that occurs naturally during DNA replication

• A mutation that results in a frameshift

How does UV radiation cause DNA damage?

• By inserting extra nucleotides

• By removing nucleotides

• By causing pyrimidine dimers

• By breaking the DNA strand

What is the role of glycosylase enzymes in DNA repair?

• To perform mismatch repair

• To seal DNA strands

• To initiate base excision repair

• To repair pyrimidine dimers

Which repair mechanism is used to fix pyrimidine dimers?

• Nucleotide excision repair

• Base excision repair

• Silent mutation repair

• Mismatch repair

Why is it important to wear sunscreen?

• To enhance DNA repair mechanisms

• To avoid spontaneous mutations

• To prevent chemical mutations

• To protect against UV-induced DNA damage