Week Six (Genomes and their Evolution) Flashcards
Where gene density differs
Gene density is higher in prokaryotes
More density density variability in eukaryotes (due to presence of introns)
Where genome size differs
Genome size more variable in eukaryotes
Where gene number differs
Different peaks (eukaryotic has bigger base)
Alu elements
10% of genome
May help regulate gene expression
LINE1 Transposons
17% of genome
May contribute to neuron development
Transposable elements impact on genome
- Can create translocation by unequal crossing over (deletion and duplication)
- Can disrupt/inactivate genes (no proteins produced)
- Can increase/decrease gene expression
Types of repetitive DNA
Large segment duplication (one region to another)
Simple sequence DNA (repeats, further divided to short tandem repeats)
Where is simple sequence DNA found
Found near telomeres playing a structural role
Mechanisms of how gene structure can change
Translocation and fusion (lead to emergence of new species)
Nondisjunction (one set provides function while the other mutates)
Unequal crossing over (duplications and deletions)
DNA polymerase slip during replication (short tandem repeats)
How multigene families and new proteins can evolve
Same ancestrial gene expressed at different development stages
Duplications result in mutations
Exon shuffling, duplication and deletion leading to mutation