Lecture 3: DNA Replication, Repair, and Recombination

A set of flashcards covering key concepts from Lecture 3 on DNA replication, repair, and recombination, designed to aid in exam preparation.

What is the role of germ cells in genetics?

Germ-line cells pass on genetic information into the next generation.

What is a somatic cell?

Somatic cells are all of the cells in the body that do not pass genetic information onto the next generation.

What is semiconservative DNA replication?

DNA replication in which each new DNA strand contains one original strand and one newly synthesized strand.

Which direction does DNA Synthesis take place?

5’ to 3’

What is the function of RNA primers in DNA replication?

They are synthesized by DNA primase and are about 10 nucleotides long, made at intervals on the lagging strand.

What are Okazaki fragments?

Short segments of DNA synthesized discontinuously on the lagging strand during DNA replication.

Why are Okazaki fragments created?

They are created because DNA synthesis can only occur in the 5' to 3' direction, so on the lagging strand that is 3’ to 5’, the fragments are created in short bursts to accommodate this directionality.

What are the three steps that contribute to high-fidelity DNA synthesis?

5' to 3' polymerization, 3'→ 5' exonucleolytic proofreading, and strand-directed mismatch repair.

What types of damage can cause double-strand breaks (DSBs) in DNA?

Ionizing radiation, replication errors, oxidizing agents, and metabolites produced in the cell.

What is homologous recombination (HR)?

Genetic exchange that occurs between homologous DNA sequences, crucial for repairing double-strand breaks.

What can result from faulty DNA repair processes?

Genetic syndromes and increased susceptibility to diseases such as cancer.

What is the significance of maintaining genome integrity?

It is crucial for the survival of organisms, as mutations can lead to diseases, including cancer.