Telomerase and DNA Replication Concepts

The video tutorial explains DNA synthesis in prokaryotes and the unique challenges faced in eukaryotes, particularly at the chromosome ends. It highlights the role of RNA primers in providing a free 3-prime hydroxyl group for DNA polymerase. The video discusses the problem of incomplete lagging strand synthesis and introduces telomeres and telomerase as solutions to prevent chromosome shortening. Telomerase extends the parental strand using an RNA template, allowing the lagging strand to be completed. This process ensures that no genetic information is lost during cell division.

What unique problem arises when the replication fork reaches the end of a chromosome?

• The replication fork collapses.

• There is no free 3-prime hydroxyl group for DNA polymerase to extend.

• The DNA polymerase runs out of nucleotides.

• The leading strand cannot be completed.

What is the role of RNA primers in DNA replication?

• They prevent DNA strands from tangling.

• They repair DNA strands.

• They terminate DNA synthesis.

• They provide a starting point for DNA polymerase.

Why can't the end of the lagging strand be completed after the final RNA primer is removed?

• There is no free hydroxyl group for DNA polymerase to synthesize new DNA.

• The DNA polymerase is inactive.

• The leading strand blocks the lagging strand.

• The replication fork is too far away.

What happens to the chromosome ends if the gaps in the lagging strand are not filled?

• They duplicate.

• They become longer.

• They remain unchanged.

• They shorten with each cell division.

What are telomeres?

• RNA molecules that assist in DNA replication.

• Proteins that bind to DNA.

• Enzymes that synthesize DNA.

• Repetitive nucleotide sequences at the ends of chromosomes.

What is the function of telomerase?

• To initiate DNA replication.

• To remove RNA primers.

• To add repetitive sequences to the ends of chromosomes.

• To degrade telomeres.

How does telomerase elongate the parental strand?

• By adding random nucleotides.

• By binding to the lagging strand.

• By using an RNA template.

• By using a DNA template.

What mechanism does telomerase use to synthesize DNA?

• Reverse transcription.

• Forward transcription.

• Direct transcription.

• Lateral transcription.

Which enzyme completes the lagging strand after telomerase action?

• DNA polymerase beta.

• DNA polymerase delta.

• DNA polymerase gamma.

• DNA polymerase alpha.

What is the significance of telomeric replication?

• It promotes cell aging.

• It inhibits DNA damage.

• It accelerates DNA replication.

• It prevents chromosome shortening during cell division.