Lecture--Chapter 13 Flashcards Preview

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Flashcards in Lecture--Chapter 13 Deck (85)
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61

synthesises telomeres on one strand using its own RNA template

telomerase

62

gradually shorten, which limits cellular life-spans

telomeres

63

the exchange of DNA between similar or identical segments is found in all species

homologous recombination

64

Homologous recombination is best understood in ____.

E. coli

65

In eukaryotes, homologous recombination usually occurs in ____.

meiosis I

66

Exchange of DNA between non-sister ____ of homologous chromosomes.

chromatids

67

Proposed by Robin Holliday in 1964 based on studies of fungi

The Holliday Model

68

a mobile junction that forms between 4 strands of DNA

Holliday junction

69

The Holliday junction must be ___ to restore duplex DNA.

separated

70

The Holliday Model: homologous chromosomes align and are ____.

nicked

71

The Holliday Model: a single strand separates from its complementary strand, and basepairs with its complement in the sister chromatid

strand invasion

72

The Holliday Model: ______ formation between the 4 strands.

Holliday junction

73

The Holliday Model: ____ can continue for some distance along the chromatid and form a ____. This is known as ___.

strand swap; heteroduplex; branch migration

74

The Holliday Model: eventually another nick may stop the process and the strands are rejoined

resolution

75

The Holliday Model: both chromatids are nicked at _____ locations.

identical

76

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.

left; right

77

The Holliday Model: The Holliday junction migrates from ___ to ____. This is called ____. It creates 2 ____ regions.

left; right; branch migration; heteroduplex

78

The Holliday Model: Two heteroduplex regions that have a few base _____.

mismatches (heteroduplex DNA)

79

Double-Strand Break Model: both backbones are broken in one ___, and some DNA is degraded.

chromatid

80

Double-Strand Break Model: ____ uses the other chromatid as a template for replacing lost DNA.

Gap repair function

81

Double-Strand Break Model: Gap repair function produces 2 _____.

Holliday junctions

82

one allele can replace the alternate allele

gene conversion

83

Gene conversion: DNA ___ repair or DNA ___ repair.

gap; mismatch

84

Gene conversion: DNA repair will _______.

correct the mismatches of heteroduplexes

85

chance of sequence of the invading strand being used as a template for correction:

50/50