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HIGHER BIOLOGY
Unit 1
1.7 + 1.8 - evolution and genomic sequencing
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Eilidh Robertson
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Cards (29)
define evolution?
the changes in
organisms
over
generations
as a result of
genomic
variations
Define natural selection?
the
non random increase
in the frequency of
DNA sequences
that increase
survival
the
non random reduction
in the frequency of
deleterious
sequences
what are selection pressures?
any reason for organisms with certain
phenotypes
to have either a
survival
benefit or
disadvantage
what are the 3 selection pressures?
stabilising
directional
disruptive
define stabilising selection?
natural selection
where an
average phenotype
is
selected
for and
extremes
of the
phenotype range
are
selected against
Define directional selection?
Natural
selection where
one extreme
of the
phenotype
range is selected for
define disruptive selection?
natural selection where
two
or
more
phenotypes are selected for
What kind of selection pressure is this?
stabilising
selection
what kind of selection is this?
directional
selection
what kind of selection is this?
disruptive selection
define horizontal gene transfer?
transfer
of genes between individuals in the
same generation
define vertical gene transfer?
genes are transferred from
parent
to
offspring
as a result of
sexual
or
asexual
reproduction
Natural selection is more rapid in
prokaryotes
because they can exchange genetic material
horizontally
Define speciation?
the generation of new biological
species
by evolution as a result of
isolation
,
mutation
and
selection
define species?
a group of
organisms
that can
interbreed
to produce
fertile
offspring
, and which does not normally
breed
with other groups
Why are isolation barriers important?
prevent
gene flow
between
sub-populations
during
speciation
allopatric speciation comes from
geographical
barriers
Sympatric speciation comes from
behavioural
and
ecological
barriers
In genomic sequencing, the sequence of
nucleotide
bases can be determined for individual
genes
and entire
genomes
How do you compare sequence data?
computer
and
statistical
analyses (
bioinformatics
)
what does the comparison of genomes reveal?
genes are
highly
conserved
across different organisms
what are the three domains of life?
Bacteria
archaea
eukaryotes
What are two sources of evidence which can provide information used to products phylogenetic trees and molecular clocks?
sequence
data
fossil
evidence
land
plants
are the most recently occurring evolutionary event
Cells
are the oldest occurring evolutionary event
list the sequence of evolutionary events from oldest to newest?
cells
last universal ancestor
prokaryotes
photosynthetic organisms
eukaryotes
multicellularity
animals
vertebrates
land plants
Define phylogenetics?
the study of
evolutionary history
and
relationships
What is sequence data used for?
to show
evolutionary relatedness
between groups of organisms
How can an individuals genome be analysed to predict the likelihood of developing certain diseases?
pharmacogenetics
personalised medicine