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Flashcards in Lecture 4 Deck (7)
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1

what is the structure of chromosomes

highly coiled fibre of chromatin wrapped around histone proteins

2

structure of histones

8 subunits
highly charged
can move back and forth to open up sites of DNA for replication

3

what are linker histones

H1
strap DNA onto histone octamers
stabilises and facilotates establishment of silent DNA

4

what are telomeres

specialised ends of chromosomes that maintain integrity
replicates by telomerase
TTAGGG

5

what are centromeres

where kinetochores assemble
contain alpha-satelite DNA repeats
bind to inner plate kinetochore proteins
outer plate kinetochores bind to spindle
contains specialised histone CENP-A taht mediates attatchemnt of chromosome to kinetochore
and H3-K4ME that helps to hold sister chromatids together

6

the more complex the organism the more

protein encoding parts
non protein encoding DNA

7

what are the three different transposons

DNA transposon
retroviral retrotransposons
non-retroviral poly A transposons
mobile genetic elements that jump around genome