Transcript 5.5 Classification

How did the Greek philosopher Aristotle classify organisms? What were the problems with this
method?
What is taxonomy?
What is the binomial System of classification? Who came up with this system? When?
What is genus? What is species?
What are the 7 levels of hierarchy in classification?
Give one example of an animal and plant and their whole hierarchy of classification.
What are the 5 kingdoms?
What are the characteristics of the plant kingdom?
Give examples and characteristics (physical, simple external recognition) for Bryophyta,
Filicinophyta, Coniferophyta, Angiospermophyta.
What are the characteristics of the animal kingdom?
Give examples and characteristics (physical, simple external recognition) for Porifera, Cnidaria,
Platyhelminthes, Annelida, Mollusca and Arthropoda.
What is a dichotomous key? Give an example.
Assessment Statements
Outline the binomial system of classification
List seven levels in the hierarchy of taxa- kingdom, phylum, class, order, family
genus and species- using examples from two different kingdoms for each level
Distinguish between the following phyla of plants, using simple external
recognition features: bryophyta, filicinophyta, coniferophyta,
angiospermophyta.
Distinguish between the following phyla of plants, using simple external
recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca
and arthropoda.
Apply and design a key for a group of up to 8 organisms.
You failed your Latin exam!? But sweetie all of your friends’ names
have Latin roots!
Why Classify
Biological classification attempts to arrange
living organisms into groups that enable them
to be identified easily and that show
evolutionary links between them.
The system we use today was originally
devised by the Swedish scientists Carolus
Linnaeus (1707-1778).
It allows us to group similar organisms
The Binomial System of Classification
The classification of living organisms
is simply a method of organizing
them into groups to show similarities
and differences.
(384-322 BC) Greek philosopher
Aristotle classified organisms into two
groups- plants and animals.
This was a useful starting point, but
as the two main groups were subdivided, problems appeared.
At this time organisms were
considered unchanging and
evolutionary concepts weren’t
understood.
Organisms later discovered didn’t fit
into this scheme.
Birds were separated into a group defined as “Feathered animals that can
fly”
So no place could be found for the flightless birds such as a kiwi or ostrich.
Bacteria, which were unknown at the time, weren’t included at all.
1735, Carolus Linnaeus adapted Aristotle’s
work, and his system forms the foundation of
modern taxonomy.
Taxonomy is the science od identifying, naming
and grouping organisms.
Linnaeus gave each organism two Latin
names- the first part of the name is the genus
name and the second part is the species
names.
The binomial, or two-part, name for the
American grizzly bear is Ursus americanus
A polar bear would be Ursus maritimus
It is important that when scientists in Mongolia work on a
species, a scientist in Brazil knows which one.
Anemone
Anemone
He used Latin for his names because it was the language of
medicine and science, and it is unchanging.
Ursus americanus
Ursus maritimus
The genus part of the name indicates a group of species that are
very closely related and share a common ancestor.
The species is usually defined as a group of individuals that are
capable of interbreeding to produce fertile offspring.
Linnaeus devolved a structure in his classification system.
He grouped birds into birds of prey, wading birds and perching birds.
Although it’s possible to group living things in many different ways a
hierarchical classification system has emerged that all biologist use.
There are 7 levels of Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
Make up a pneumonic to remember
this list in order.
King Philip Comes Over For Great Sausages.
The 5 Kingdoms
Animalia
Plantae
Fungi
Protist
Bacteria
No cell
walls
Cellulose
cell walls
Chitin cell
walls
Many types
of cell wall
NAG-NAMA
cell walls
Multicellular
Multicellular
Single +
Multicellular
Single
cellular
Single
cellular
Saprotroph
Many
feeding
types
Many
feeding
types
Heterotroph Autotrophs
Polar Bear
Lemon Tree
Kingdom
Animalia
Plantae
Phylum
Chordata
Angiospermata
Class
Mammalia
Dicoyledoneae
Order
Carnivora
Geraniales
Family
Ursidae
Rutaceae
Genus
Ursus
Citrus
Species
Maritimus
limonia
A closer look at Plants:
There are 4 phyla:
1. Bryophyte – The mosses
2. Filicinophyte – The Ferns
3. Coniferophyte – The Conifers
4. Angiospermophyte – The flowers
BRYOPHYTES – THE MOSSES
Usually small and grow in damp places
Simple non, vascular (no xylem and phloem.)
No proper roots but have rhizoids
Reproduce with spores (in a capsule on a stalk). Male gamete swims to female!
FILICINOPHYTES – THE FERNS
Group includes club mosses, horsetails and ferns
Has stems roots and leaves. Because of support from woody tissue they can grow up to 5m
Reproduces by spores (underside of the leaves). Male gamete swims to female.
Some have fibrous roots, while others produce an underground stem called a rhizome.
CONIFEROPHYTES – THE CONIFERS
Includes shrubs, or trees such as pine, fir, cedar
which are large and evergreen, some of the
tallest trees in the world.
Truly vascular. Reproduce with pollen. Make cones
with seeds inside.
Leaves are needle shaped to conserve water.
ANGIOSPERMOPHYTES- FLOWERING
PLANTS
Contains flowering plants, which are pollinated by wind or animals.
Range from small low-lying plants to large trees. Many are important crops
Have proper flowers which produce pollen. All produce seeds which are associated with
nuts and fruit.
Truly vascular.
THE ANIMAL INVERTEBRATES IN DETAIL
Invertebrates are animals without backbones there are 6
phyla:
1.
2.
3.
4.
5.
6.
Porifera – sponges.
Cnideria - corals.
Platyhelminthes – flat worms.
Annelida – segmented worms.
Mollusca – snails, octopi.
Athropoda – insects, spiders, crustaceans
Animal kingdom are characterized by being able to move and getting nutrients by
eating plans, other animals or both. Animals are divided into two groups- with a
backbone (vertebrates) and without (invertebrates).
PORIFERA – THE SPONGES
This group contains sponges.
They have different types of cells, but no real organization into tissues
No clear symmetry
All are aquatic
Pump water through numerous pores and filter food.
No nerves or muscular tissue.
CNIDERIA – CORALS, HYDRA, JELLYFISH
These are sea anemones, corals, jellyfish.
All most all marine, cells are organized into tissues in two body layers
They feed on other animals by stinging them with nematocyst
They have a mouth t take in food and use the same opening to get rid of
waste.
PLATYHELMINTHES- FLATWORMS
These have 3 layer of cell and have a body cavity with
a mouth and anus
Some are free living while others are parasites.
Flattened appearance, most are small but tapeworms
may grow to several meters.
ANNELIDA – SEGMENTED WORMS
Contains earth worms and
leeches,
Some are aquatic, others in
the soil.
All have a simple gut with a
mouth at one end and an
anus at the other.
Earthworms are important to
agriculture because
burrowing aerates the soil.
MOLLUSCA – SNAILS, OCTOPI
Have a mouth and anus.
Bilateral symmetry.
Most have a calcium carbonate shell.
Hard rasping ‘radula’ is used for feeding.
ATHROPODA – INSECTS,
SPIDERS, CRUSTACEANS
Largest animal phylum.
All have exoskeleton made of chitin, places
restrictions on how large they can get because
they have to shed it in order to grow.
Segmented bodies and jointed limbs.
Over a million different types and many more
being discovered.
A dichotomous key is a series of steps,
involving a decision, that can be used to
identify unknown organisms.
They prompt us to decide, through careful
observation, whether or not a specimen
displays a particular visible feature.
When constructing a key examine each
specimen and choose a characteristic that is
present in about half and absent in the
other.
Now split those groups in half based on a
visible characteristic.