Genome Maintenance

What are the three main DNA repair mechanisms?

• direct repair, double-strand break repair, and homologous recombination

• mismatch repair, nucleotide excision repair, and direct repair

• transcription-coupled repair, non-homologous end joining, and base excision repair

• base excision repair, nucleotide excision repair, and mismatch repair

What is the primary function of DNA repair mechanisms?

• To correct damage to the DNA molecule and maintain the integrity of the genetic information.

• To replicate DNA molecules

• To break down DNA molecules

• To create new DNA molecules

What is the structure of a nucleosome?

• A nucleosome consists of RNA wrapped around a core of histone proteins.

• A nucleosome consists of DNA wrapped around a core of non-histone proteins.

• A nucleosome consists of DNA wrapped around a core of histone proteins.

• A nucleosome consists of RNA wrapped around a core of non-histone proteins.

What is the role of histones in chromatin structure?

• Histones are responsible for DNA replication.

• Histones are involved in RNA transcription.

• Histones protect DNA from damage.

• Histones organize and compact DNA into a condensed form.

Which DNA repair mechanism is responsible for fixing double-strand breaks?

• homologous recombination

• mismatch repair

• non-homologous end joining

• base excision repair

What is the purpose of DNA repair checkpoints in the cell cycle?

• To speed up cell cycle progression.

• To ensure DNA damage is repaired before cell cycle progression.

• To prevent DNA damage from occurring in the cell cycle.

• To ensure DNA replication occurs before cell cycle progression.

How does DNA repair contribute to genome stability?

• DNA repair contributes to genome stability by breaking down damaged DNA molecules.

• DNA repair contributes to genome stability by introducing mutations into the DNA molecules.

• DNA repair contributes to genome stability by promoting the accumulation of mutations.

• DNA repair contributes to genome stability by fixing damaged DNA molecules and preventing the accumulation of mutations.

What is the difference between heterochromatin and euchromatin?

• Heterochromatin is loosely packed and transcriptionally active, while euchromatin is tightly packed and transcriptionally inactive.

• Heterochromatin and euchromatin have the same level of packing and transcriptional activity.

• Heterochromatin and euchromatin are both transcriptionally inactive.

• Heterochromatin is tightly packed and transcriptionally inactive, while euchromatin is loosely packed and transcriptionally active.

What is the role of chromatin remodeling complexes in genome maintenance?

• Chromatin remodeling complexes have no role in genome maintenance.

• Chromatin remodeling complexes cause DNA mutations and instability.

• Chromatin remodeling complexes are only involved in gene expression, not genome maintenance.

• Chromatin remodeling complexes regulate DNA accessibility and maintain genomic stability.

What are the consequences of defects in DNA repair mechanisms?

• Increased risk of mutations, genomic instability, and development of diseases like cancer.

• Decreased risk of mutations, genomic stability, and prevention of diseases like cancer.

• Enhanced DNA repair mechanisms and improved overall health.

• No impact on mutations, genomic stability, and disease development.