Genomic DNA and Nucleic Acids Prework 2 Flashcards Preview

MCM Test 1 > Genomic DNA and Nucleic Acids Prework 2 > Flashcards

Flashcards in Genomic DNA and Nucleic Acids Prework 2 Deck (11):
1

what percentage of DNA is repeated sequences?

50%

2

what are the two types of repeats in DNA and how do they differ?

interspersed: repeated at different intervals on the chromosome
tandem: repeated over and over right next to each other

3

what are the 4 classes of interspersed repeats in the human genome and what % do they make up?

LINEs- 20%
SINEs- 13%
HERVs- 8%
DNA transposon fossils- 3%

4

what are LINEs?

transposons, move via RNA intermediates
6000 nt long, 850,000 copies

5

what are SINEs?

inactive, but movement can be facilitated by active transposons
Alu repeats
280 nt long, 1.5 million copies

6

what phenomenon can long interspersed repeats facilitate?

non-homologous recombination

7

what are 3 types of tandem repeats?

satellite DNA: 3-5% of DNA in each chromosome
minisatellite DNA
microsatellite DNA

8

where are satellite DNA sequences located at each chromosome?

centromere; binding sited for proteins involved in centromere structure

9

what can micro- and minisatellite DNA repeats be used for?

DNA fingerprinting

10

what are segmental duplications?

regions >1kb with greater than 90% identity, present more than once in the genome
duplications can be on the same or multiple chromosomes
5% of genome

11

how do segmental duplications contribute to genomic rearrangements?

unequal crossing over in meiosis