W3

• Transposable elements


  The actual genetic elements that move around
• Transposons


  Parasitic DNA sequences that can spread within genomes they colonize, also called jumping genes
• Microsatellite DNA


  1. 5 bp of DNA that scatter in clusters of 10-40 bp throughout the genome. These are used to compare closely related populations
• Tandem Repeats


  Nucleotide sequences that repeat over and over without interruption
• Orthologs


  Similar genes between two different species that evolved from the same gene but were separated by something like speciation
• Conserved DNA


  DNA regions that are most likely functionally important because the loss of these would impair the organism's function and cause its elimination from the gene pool
• Retrotransposons


  Transposable elements that use a mechanism which involves an RNA intermediary
• Conserved DNA: 4.5% of human DNA exists across species, with about one quarter being protein coding and the rest believed to code for RNA that doesn't become protein or exist as protein binding sites for gene regulation
• Exon shuffling


  Rearrangement of gene coding or regulatory sequences
• Homologous genes


  Genes that have similar nucleotide sequences and functions
• Reverse transcriptase


  The enzyme that allows the reverse transcription of RNA to DNA that retrotransposons use
• DNA polymerases


  Add new nucleotides to growing strands of DNA in the 5' to 3' direction
• Mobile DNA


  DNA that moves from one place to another in the genome
• Satellite DNA


  DNA generally found at centromeres and telomeres that is 5-500 bp in tandem
• Single nucleotide polymorphism


  Most common variability among humans that only contributes to phenotypic differences if it's in protein coding regions
• Purifying selection


  Selection that eliminates individuals carrying mutations
• Slippage


  Repetitive DNA sequences misalign due to this. It can lead to DNA being expanded or destroyed
• Paralogs


  Similar genes in the same species that came from the same gene but have now diverged
• Copy number polymorphism


  Difference in the number of copies of a particular sequence
• MutS and MutL


  Proteins involved in strand-directed mismatch repair that recognizes distortions in the double helix and repairs them
• Transposase enzyme


  Enzyme that allows transposons to move using a cut and paste system
• Unequal crossing over


  Mutation in DNA caused by misalignment of DNA before crossing over
• Point mutations


  Individual nucleotide swaps
• Microsatellite instability


  DNA mutations caused by DNA machinery being inoperable due to mutations. This can contribute to disease progression in humans
• Minisatellite DNA


  10-100 bp of DNA that can have up to 3000 repeats. This is also the basis for DNA fingerprinting
• Pseudogenes


  Genes that are similar to the gene family but have accumulated so many mutations they're non-functional
• LINEs and SINEs


  Examples of retrotransposons
• Synteny


  Blocks of DNA where gene order is the same in different species but location on a chromosome has changed
• Single-stranded DNA absorbs more UV light
• Transposition


  The actual process of DNA moving and genetic rearrangement
• Homologs


  Any genes that share similarity because of common ancestry/origin
• Inverted repeats


  Sequence required on the ends of the transposon for transposase to recognize the transposon