genome structure Flashcards
what is a genome?
entire nucleic acid information in each cell
used to develop the organism
what is a viruses genome like?
very variable DNA or RNA ss or ds coding or template overlapping or multfunctional
prokaryote genomes
compact and small
circular
arranged into operons
plasmids are optional extras
eukarytic genomes
large
organised to chromosomes
operons rare
genes dont group into functions
do eukaryotic genes group?
not into functions
but sometimes essential genes tend to be near each other
what are organellar genomes like?
some such as mitochondria and chloroplasta have their own
genomes are separate due to endosymbiosis
what is a protist?
diverse grop of unicellular eukaryotes
what are protist cell nucleus like?
two kinds:
micronucleus: heriditary and used in sex
macronucleus: working memory, data here to make proteins
key features of protists genomes
genome edited in strange ways
ccan edit it before being translated into proteins
what is a centromere used for?
at the middle of a chromosome and used for cell division and pulling it apart
whats a telomere used for
ends of the chromosomes
what is a chromosome made up of/
heterochromic repetetice DNA
how are sex chromosomes structured?
XY in mammals
how an sex chromosomes be structured in birds, moths and butterflies
WZ
females have WZ
males ave ZZ
types of chromosomal mutations
replication errors deletion duplication translocation aneuploidy
what does ploidy mean?
number of sets
define karotype
number of chromosomes in a cell
what ploidy are humans?
diploid
what is compartive genomics
detecting conservation/divergence of sequences but alos the gene content and order
syntenty
what can comparitive genomics look for?
evidence for duplications of chromosome regions or whole genome duplications
what is the C-value paradox
graph of the genome size
looks at the correspondance between complex organisms and genome size
what does the c-value paradox expect
expect more compacted we are the more genes would be needed
but this doesnt happen
the relationship between organism size and genome size is a loose/not good.
what does appear to be driving genome size and complexity?
something other than complexity
to do with repetetive DNA as this doest do much for the organism
why are humasn bad model organisms
very long generation time
small little size
ethical issues
what is the human genome project of 1988
megaproject to sequence human DNA
two projects for sequencing human genome
IIHGP
Celera
how did IHGP go about go about the human genome project?
work was public and open acces
used chromosome walking and bacteria artficial chromsomes BACs
kab work intensive
how did celera go about squencing the human gneome?
commercial
shutgun sequencing, computationally intensive
take genome and cut it nd sequence small bits
more complicated but less lab work
one human sequenced
what were the results of the human genome project?
less genes that expected
some genes shared with lots of other animals
largely introns and repetive stuff
what percentage of the huma gneome codes for proteisn?
2%
how did the human genome project explain the c-value paradox
most of the huma genome is selif-replicating dna parts that dont contribute to DNA
proportion of genes isnt key but the amoutn of repetitive stuff is
what is the current state of the human genome project?
not fully sequenced yet
250 gaps
confident, few errors
how many base pairs do we have?
3.2 billion
what is miotchondrial eve
following the ancestral female line takes back to a common ancestor
maternal line for everyones mitochrondra
how are humans variated?
highly homogenous
SNP and small CNV differences
people are more diverse to each other than populations
what genes differ between populations
skin
hair morphology
immune genes
earwax
