W2 Chromatin + Chromosomes Flashcards
why do some areas of DNA need to be packed more/less
- to control gene expression
- more packed = polymerase cant bind for transcription
what does an area of dense transposons mean
- less transposon movement
where are regions of gene expression found
euchromatin regions
why does histones have more Lysine and Arginine AA
more +ve to bind to negative DNA
what’s good about gene duping
prevents mutations from affecting genes
how do mobile DNA elements move
by the enzyme = transposase
what is an outcome of transposition
can cause mutations
how does the insertion of a transposon affect genes
- disrupt regulatory sequence
- start mutations at break sites
how to retroviruses exist
as ssRNA
how do retroviruses like HIV integrate into host cell
conversion of viral RNA to dsDNA
what are retrotransposons
- mobile elements that cant move themselves
- don’t have protein coat
what are 2 examples of non-retroviral retrotransposons
LINEs + SINEs
how much of genome is made of non-retroviral retrotransposons
30%
what are the 3 things junk DNA normally known as
- regulatory elements
- regulatory RNAs
- ancestral genes
what are introns and their function
- non coding regions within genes
- gene expression regulation
