classification Flashcards
define classification
process by which organisms are sorted into groups
what are the taxonomic groups
kingdom
phylum
class
order
family
genus
species
what caused the addition of the domain class
genetic analysis
why do scientists classify organisms
identify species
predict characteristics
find evolutionary links
define species
group of organisms that are able to reproduce to produce fertile offspring
why do organisms produced from reproduction between species
odd number of chromsomes
before classification how were organisms ordered
observable physical characteristics, behaviour or habitat (common names)
why is binomial nomenclature used
useful for scientists working internationally
define animal kingdom
organism that moves, ate, grew to certain size and stopped growing
define plant kingdom
organisms that doesn’t move, eat and grows throughout their life
what are the 5 kingdoms
prokaryotae
protoctista
fungi
plantae
animalia
define woese’s system
uses difference in the sequence of rRNA and cells’ membrane structure and their sensitivity to antibiotics
what are the 3 domains
eukarya
archaea
bacteria
where are archeabacteria found
can live in extreme environments
where are eubacteria found
found in all environments
define phylogeny
evolutionary relationships between organisms
what are advantages of phylogeny
can be don without reference to linnaean classification
produces a continuous tree
define evolution
describes the way organisms change over time as a result of natural selection
define uniformitarianism
the earth is shape by forces that are still in action
why is it an advantage that darwin brought back organisms for other scientists to analyse
enable scientists to see specimens first hand
and spot characteristics and links between organisms that darwin had not
how are fossils formed
when organisms remains are preserved in rocks
what is a negative of fossil record
incomplete
soft-bodied or those that decompose quickly don’t have a chance to fossilise
and conditions needed for fossils to form aren’t always present
define divergent evolution
different species have evolved from a common ancestor
how is comparative biochemistry plotted
number of differences that exist plotted against the rate the molecule undergoes neutral base pair substition
how does comparative biochemistry work
scientists can estimate the point at which the 2 species last shared a common ancestor
when calculating std. deviation, you will find:
68% of values are within 1 s.d. of the mean
95% of values are within 2 s.d. of the mean
99.7 of values are within 3 s.d. of the mean
what are the types of adaptations
anatomical
behavioural
physiological
define a xerophyte
organism that is adapted to live in an environment with little water
what are adaptations common in xerophytes
curled/rolled leaves – minimise SA of moist tissue
hairs trap moist air close to leaf to reduce gradient
stomata sunk into pit – make them less likely to open
thick waxy cuticle – reduces water loss
define analogous structures
structures adapted to perform the same function but have different genetic origin
define convergent evolution
when an unrelated species begins to share similar traits
how might convergent evolution come about
organisms adapt to similar environments or selection pressures
what is an example of convergent evolution
marsupial and placental mammals
what are the potential benefits of coppicing for biodiversity
lifespan of tree extended
provides variety of light levels
more light for smaller plants
provides variety of habitats
roots prevent soil erosion
maintains soil quality
prevent succession
what happens to other types of diversity if habitat diversity increases
species diversity increases because more species live in new habitats
genetic diversity increases as species have a wider range of conditions in which to live in
how does creating dams improve the diversity of the ecosystem
reduced flow rate downstream creating still water
slow moving water for aquatic species
how does felling trees by beavers improve the diversity of the ecosystem
opens up tree canopy allowing light to ground level
how does building lodges improve the diversity of the ecosystem
creates sheltered habitats for insects
what might be arguments against the impact of beavers on rural businesses
evaluate their arguments
loss of farmland due to flooding
strength of argument depends on the area affected
probably not strong argument as relatively small areas are affected
trees cut down
likely in area near water so not a strong argument
how can a species evolved from an ancestor in a separated land
allopatric speciation
different selection pressure
mutation
individuals with mutation reproduce
alleles passed on
directional selection
what are conditions needed for speciation to occur
mutation
natural or directional selection
selection pressure is different from other populations
time
