2. BIODIVERSITY
• The variability among living organisms
from all types of ecosystem (e.g.
terrestrial, marine)
• This includes diversity
– within species
– between species
– of ecosystems
3. TAXONOMY – classification
• All living organisms are classified into
different groups.
• This allows a kind of ‘filing system’ so that
any new discoveries are easily incorporated
into a group and relationships between
groups of similar organisms can be studied.
• It also makes international communication
easier and more efficient. That is because all
new discoveries will have recognised names
which are the same in all countries, and
they will all belong to a universally accepted
groups.
4. Kingdoms
• In the system we use, all living organisms
are split into 5 kingdoms.
• Viruses do not fit into this classification –
they are not regarded as living organisms
The 5 kingdoms are called:
1. Prokaryota (bacteria)
2. Protista
3. Fungi
4. Plantae
5. Animalia
5. The way a kingdom is split into smaller groups is as
follows:
This is a hierarchical system – in which large groups are split into
smaller groups based upon their similarities and differences.
• each kingdom is divided into phyla
• each phylum is divided into classes
• each class is divided into orders
• each order is divided up into families
• each family is divided up into genera
• each genus is divided up into species
6. The Animalia Kingdom
Useful tip: Use the following
sentence to prompt you for the
first letter for each level:
Keen Pupils Choose Our
Fantastic Groovy School
Each of these levels is called a
TAXON (plural: taxa)
Kingdom e.g. Animalia
Phylum e.g. Chordata
Class e.g. Mammalia
Order e.g. Primates
Family e.g. Hominidae
Genus e.g. Homo
Species e.g. sapiens
7. TAXA
• In a taxon, members all share one or
more common features (or
homologies)
• It is generally presumed that they have
a common evolutionary ancestor
• In evolutionary terms, members of a
taxon are more closely related than to
any other organisms outside that
taxon.
8. Here is a table which shows the features of each
of the 5 kingdoms:
BACTERIUM
AMOEBA
MOULD
YEAST
TOADSTOOL
Prokaryota: Protoctista: Fungi:
Cell type Prokaryotic
Very small
Typically
<10µm across
Eukaryotic Eukaryotic
Organisation Unicellular
No distinct
nucleus
A single
circular
chromosome
No
membrane-
bound
organelles
Multicellular
or unicellular
Simple basic
body
structure
Multicellular
Most are
made up a
network of
thread-like
strands called
hyphae
Cell walls
made of chitin
Nutrition Miscellaneous Either
photosynthesi
se or feed on
organic
matter
Heterotrophic
- mostly
saprobiontic
(decay)
- no photosyn
Reproduction Mostly
asexual
Asexual
and/or sexual
Most have
sexual and
asexual
Examples Bacteria /
Cyanobacteri
a
(blue-green
bacteria)
Algae /
Protozoa
e.g. Amoeba
and
Paramecium
Mould / Yeast
/ Mushrooms
9. Plantae: Animalia:
Cell type Eukaryotic Eukaryotic
Organisation Multicellular
Differentiated cells
organised into
specialised organs
Cellulose cell walls
Chloroplasts and large
vacuoles
Multicellular
Differentiated cells
organised into
specialised organs
No cells walls,
chloroplasts or large
vacuoles
Most can move from
place to place
Have a nervous system
Nutrition Photosynthetic
autotrophs
- make organic
compounds
Heterotrophs
Reproduction Sexual and asexual Mostly sexual with
haploid gametes
Examples Mosses / Liverworts /
Ferns / Conifers /
Flowering plants
Jellyfish / Sponges /
Flatworms / Arthropods
Fish / Roundworms /
Birds / Mammals
10. BINOMIAL NAMES
• Each species has its own unique two-
part Latin binomial name, made up of
the genus and species names
• This was first introduced by Carl
Linnaeus.
11. Species
• The species is the lowest level of
classification within each Kingdom.
• All members of a species:
– have a similar morphology (body features),
physiology (how organs and body systems
function), and behaviour
– are capable of interbreeding to produce fertile
offspring
– are reproductively isolated (in time, place or
behaviour) from other species.
12. Genus
• A genus is a group of similar or closely related
species
• For example: Ranunculus = genus name for
buttercups.
• The Ranuculus genus includes:
Ranunculus aquatalis = water crowfoot
Ranunculus repens = creeping buttercup
• A genus could include just one species in some
examples, but more often it includes several
species.
13. Ranunculus repens (creeping
buttercup)
• The GENUS name starts
with a capital letter
• The SPECIES name starts with a lower case
letter
• When the binomial name is typed, it is typed
in italics
• When the binomial name is hand-written, it is
underlined
14. USING KEYS TO IDENTIFY
ORGANISMS
• Dichotomous keys have 2 alternatives to choose from at each stage
of the key
• These are artificial classifications based upon easily visible features
When using a key:
• Always read both choices, even if the first seems to be the logical
one at first.
• Be sure you understand the meaning of the terms involved. Do not
guess.
• When measurements are given, use a calibrated scale. Do not guess.
• Since living things are always somewhat variable, do not base your
conclusion on a single observation. Study several specimens to be
sure your specimen is typical.
• If the choice is not clear, for whatever reason, try both divisions. If you
end up with two possible answers, read descriptions of the two
choices to help you decide.
• Having arrived at an answer in a key, do not accept this as
absolutely reliable. Check a description of the organism to see if it
agrees with the unknown specimen.