Flashcards in Lecture--Chapter 13 Deck (85)
synthesises telomeres on one strand using its own RNA template
gradually shorten, which limits cellular life-spans
the exchange of DNA between similar or identical segments is found in all species
Homologous recombination is best understood in ____.
In eukaryotes, homologous recombination usually occurs in ____.
Exchange of DNA between non-sister ____ of homologous chromosomes.
Proposed by Robin Holliday in 1964 based on studies of fungi
The Holliday Model
a mobile junction that forms between 4 strands of DNA
The Holliday junction must be ___ to restore duplex DNA.
The Holliday Model: homologous chromosomes align and are ____.
The Holliday Model: a single strand separates from its complementary strand, and basepairs with its complement in the sister chromatid
The Holliday Model: ______ formation between the 4 strands.
The Holliday Model: ____ can continue for some distance along the chromatid and form a ____. This is known as ___.
strand swap; heteroduplex; branch migration
The Holliday Model: eventually another nick may stop the process and the strands are rejoined
The Holliday Model: both chromatids are nicked at _____ locations.
The Holliday Model: The DNA strands to the ___ of the nicks invade the homologous chromosomes and attach to the strands to the ___ of the nicks.
The Holliday Model: The Holliday junction migrates from ___ to ____. This is called ____. It creates 2 ____ regions.
left; right; branch migration; heteroduplex
The Holliday Model: Two heteroduplex regions that have a few base _____.
mismatches (heteroduplex DNA)
Double-Strand Break Model: both backbones are broken in one ___, and some DNA is degraded.
Double-Strand Break Model: ____ uses the other chromatid as a template for replacing lost DNA.
Gap repair function
Double-Strand Break Model: Gap repair function produces 2 _____.
one allele can replace the alternate allele
Gene conversion: DNA ___ repair or DNA ___ repair.
Gene conversion: DNA repair will _______.
correct the mismatches of heteroduplexes