Classified depending on how closely
related they are
Kingdom
Plantae
Contain chlorophyll and are
autotrophs (make own food).
Multicellular with a rigid cell
wall to support cells.
Animalia
Heterotrophs so
have to find own
food (e.g. plants)
Multicellular.
No cell wall or
chlorophyll.
Fungi
Saprophytes (feed off dead
organisms and decaying
material).
Multicellular with cell wall.
No chlorophyll
Protoctista
Unicellular with nucleus.
(e.g. algae)
Prokaryota
Unicellular without nucleus.
(e.g. bacteria)
Subdivided into smaller categories that
have common features.
Phylum, Class, Order,
Family, Genus, Species
Viruses non-living so belong to no kingdom.
The phylum Chordata is made up
of vertebrates (with a supporting
rod running through their back.
Oxygen absorption.
Lungs
Reptiles,birds and mammals.
Gills
Fish
Amphibians
Lungs, gills and skin.
Thermoregulation.
Homeotherms.
Mammals and birds.
Poikilotherms
Fish, amphibians and reptiles.
Reproduction.
Viviparous.
Mammals.
Oviparous.
Fish, birds,
amphibians and
reptiles.
Fertilisation.
Internal
Mammals and birds.
External
Reptiles, fish and amphibians.
Some species don't
fit exactly into a
particular class. The
duck-billed platypus
is a mammal
however it lays eggs.
If organisms are
part of the same
species they can
interbreed to
produce fertile
offspring however...
Some reproduce
asexually.
Hybrids from 2 different
species can be fertile (e.g.
mallard with yellow-billed
duck) but they are not the
same species because they
have many differences
(e.g. genetics).
There can be a lot
of variation (e.g.
breeds of dogs).
Ring species are related
populations in neighbouring
areas. Species close to one
another produce fertile
offspring but ones further
apart cannot.
Binomial system gives each species a 2 part
latin name. The first part is the genus and
the second is the species (e.g. humans are
Homo sapiens). This helps scientists by...
Identifying species to
avoid confusion where
names mean different
things in different
places.
Study species by
identifying them
research can be shared.
Conserve endangered
species so we don't
confuse similar looking
species so that one isn't
protected whilst the other
becomes extinct.
Target conservation efforts by protecting
areas with a great variety of species (e.g.
tropical rainforests to prevent a huge
number being destroyed)
Keys can be used to
decipher a species by
answering a series of
questions to narrow down
the possibilities until you are
left with just one.