CELS 191 Lecture 22 Flashcards
(26 cards)
what is a genome
a complete set of all DNA of an organism, including all its genes
why was the human genome sequenced
to identify all human genes and their roles
to analyse genetic variation among humans
to sequence the genomes of several model organisms used in genetics
to develop new sequencing techniques and computational analyses
to share genome information with scientists and the general public as fast as possible
how may base pairs are in our nuclear DNA
6 billion
how many genes are we estimated to have in our nuclear DNA
less than 20,000 genes
our nuclear DNA is stored in 22 autosomes and X/Y chromosomes, how is our mitochondrial DNA stored
as many copies of a single circular molecule
how many base pairs are in our mitochondrial DNA
16,569
where does our mitochondrial DNA come from
our mothers
how many genes are in our mitochondrial DNA
37 genes
what percent of our genome codes for proteins
less than 2%
what are the key findings of the human genome project
there are fewer genes than expected (early estimates were around 50,000) - the genome is dynamic
how similar are humans to each other on s sequence level
99.9% similar
what percent of our DNA is introns
20%
what are SNPs
single nucleotide polymorphisms - sites in the DNA that commonly vary within populations
how common are SNPs
around 1 in every 300 nucleotides
where are your SNPs mostly from
your parents (there is occasional mutation that occurs)
each genome sequenced adds
variation on record
what do most SNPs do
nothing, they are just inherited variations - this doesn’t mean they aren’t useful
what does analysing common variants (genotyping) tell you
who you are related to
where your ancestors came from
disease risk/association
muscle type
how you might respond to drugs
what are the types of SNPs
linked SNPs - outside of the gene so no effect on protein production
causative SNPs - in the gene
non-coding SNPs - change to the amount of protein produced
coding SNPs - changes the amino acid sequence
what are STRs
short tandem repeats - repeats of 2-5 nucleotides, found in specific regions of the genome
what are InDels
small insertions or deletions - they are the second most common variants type in the human genome
what is cystic fibrosis caused by
a 3 nucleotide deletion
what are frame shifts and what causes them
frame shifts are change in the way DNA is read - they are caused by InDels
what are CNVs
copy number variants - chunks of DNA larger than 500bp that are present at different amounts or ‘copy numbers’ relative to a reference genome
