Recombination Part 2 Vocabulary

Flashcards on Recombination Part 2

Recombination

Exchange of DNA from homologue chromosomes.

Double Recombination

May reverse the exchange of alleles.

Heterochromatin

Compact, heavily stained regions of chromatin, mainly consisting of highly repeated noncoding DNA sequences.

Euchromatin

The rest of the chromatin, visible after chromosome condensation in mitosis or meiosis.

G-C rich areas

Areas that form more hydrogen bonds, allowing DNA to be stable even at higher temperatures.

Z-DNA

Less compact than the B form of DNA and often associated with transcription start sites.

Ascus

In fungi, a sac that contains all four products of a single meiosis.

Tetrad

The collection of the 4 spores in one ascus.

Parental ditype (PD)

A tetrad in which all four spores are parental types.

Nonparental ditype (NPD)

A tetrad in which all four spores are recombinant types.

Tetratype (T)

A tetrad with four spores of different genotypes.

Gene conversion

Change in the base sequence of one allele to that of the other allele due to heteroduplex formation and mismatch repair during recombination.

Heteroduplex

Region of DNA where the two strands originate from nonsister chromatids and thus have different base sequences.

Holliday junctions

Interlocked regions of two nonsister chromatids in recombination intermediates.

Twin spots

Patches of somatic tissue that have different genotype