7.1-7.3 Flashcards
what is the structure of genes? (what components are they made of)
control regions, exons, introns
genes encode…..
single proteins OR different isoforms
what are gene families and where do they come from
arise from gene duplication during unequal meiosis recombination
what is polycistronic TU
mRNA coding for several proteins that function together
what is monocistronic TU
most eukaryotes, each mRNA encodes a single protein
what causes exon duplication and gene duplication
unequal crossing over during meiosis
what is the level of gene density in higher eukarytoes
lower gene density (lots of non-coding gene regions)
what is the level of gene density in lower eukaryotes
higher gene density (MOSTLY coding regions)
what is DNA fingerprinting used for
comparing individual differences in simple-sequence tandem arrays
what do mobile DNA elements do
influence evolution, cause mutations that lead to diseases, enhance/repress transcription
what are DNA transposons
mobile elements that move by cut and paste mechanism
“jumping genes”
- use transposase
- inverted repeats
-direct repeats (at the target site)
what are LTR - retroposons
mobile elements that move by copy and paste mechanism
- use reverse transcriptase
- long terminal repeats
- direct repeats
what are non-LTR retroposons (SINEs)
mobile elements that move by copy and paste mechanism
- use reverse transcriptase
- AT rich regions
- direct repeats
- RNA binding protein in ORF1
- reverse transcriptase and DNA endonuclease activity in ORF2
- don’t transpose by themselves
what is the difference between DNA transposons and retroposons
transposons move by way of cut and paste while retroposons are copied and then pasted in another region of the gene
