Download 5.5 Classification - Mr Hartan`s Science Class

5.5 Classification
Taxonomy
Taxonomy is the scientific
discipline that attempts to
identify, classify and name living
things.
IB Assessment Statements
5.5.1 Outline the binomial system of nomenclature.
5.5.2 List seven levels in the hierarchy of taxa: Kingdom,
Phylum, Class, Order, Family, Genus, and Species—using an
example from two different kingdoms for each level.
5.5.3 Distinguish between the following phyla of plants, using
simple external recognition features: Bryophyta,
Filicinophyta, Coniferophyta, and Angiospermophyta.
5.5.4 Distinguish between the following phyla of animals,
using simple external recognition features: Porifera, Cnidaria,
Platyhelminthes, Annelida, Mollusca, and Arthropoda.
5.5.5 Apply and design a key for a group of up to eight
organisms.
Binomial Nomenclature System
(“Two Names”)
Swedish naturalist (1735), Carolus Linnaeus, was the first to
consolidate and popularize the naming of organisms in his
book Systema Naturae by listing and explaining the
binomial nomenclature system.
Why Classify Organisms?
1. Show evolutionary links between organisms.
2. Predict characteristics shared by members of a group.
3. Create a universal system whereby each language,
culture, or region has the same name for one organism.
The pill bug or woodlouse are common names. The
scientific name is Armadillidium vulgare. They are the
exact same organism.
Rules for Writing Scientific Names
Homo sapiens
1. Notice that the scientific name is italicized.
2. Homo is the genus name.
3. sapiens is the ‘epithet’.
4. Both words indicate the species name.
5. If writing the scientific name for a species, the name
must be underlined.
Scientific names/terms are often derived from Latin or
Greek words.
The Hierarchy of Classification
3 Domains and 5 Kingdoms
The 6 Kingdom System
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•
•
•
•
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Kingdom Bacteria: The bacteria
Kingdom Archaea: The extremophiles
Kingdom Plantae: The plants
Kingdom Animalia: The animals
Kingdom Fungi: The fungi and molds
Kingdom Protista: The protists and algae
An Evolutionary Perspective
The Seven Taxa (Nested) Hierarchy
Species that are similar are grouped into a genus
Genera that are similar are group into a family
Families that are similar are grouped into an order
Orders that are similar are grouped into a class
Classes that are similar are grouped into a phylum
Phyla that are similar are grouped into a kingdom
Kingdoms that are similar are grouped into domains
Two Examples
Plant Phyla
We can classify these phyla according to vegetative
characteristics and reproductive characteristics.
1. Bryophyta: Includes plants of very short stature
such as mosses.
2. Filicinophyta: Includes ferns and horsetails.
3. Coniferophyta: Includes cedars, junipers, firs and
pine trees.
4. Angiospermophyta: Includes all plants which
make flowers and which have their seeds
surrounded by fruit.
Key Features (Plant Phyla)
Phylum
Roots, Leaves, Stems
Max
Height
Reproductive Struct.
Bryophytes (Mosses &
Liverworts)
No roots – rhizoids ( root-like hairs). Mosses have
simple leaves/stems. Liverworts consists of a
flattened thallus.
0.5 meters
Spores produced in a capsule. The
capsule develops at the end of a
stalk.
Filicinophytes (Ferns)
Have roots, leaves and short non-woody stems.
Leaves usually curled in bud and often pinnate –
divided into pairs of leaflet.
15 meters
Spores are produced in sporangia,
usually on the underside of the
leaves.
Coniferophytes (Conifers)
Include shrubs or trees with roots, leaves , woody
stems. Leaves are often narrow with thick, waxy
cuticle.
100 meters
Seeds produced. Seeds develop
ovules on surface of scales of female
cones. Male cones produce pollen.
Angiospermophytes
(Flowering Plants/Grasses)
Flowering plants are very variable but usually
have roots, leaves, stems. The stems of flowering
plants that develop into shrubs and trees are
woody.
100 meters
Seeds are produced. The seeds
develop from ovules inside ovaries.
The ovaries are part of flowers.
Fruits develop from the ovaries., to
disperse the seed.
Self-Assessment
A. Roots, leaves and short non-woody stems. Leaves are usually
curled up in bud and pinnate. Spores are produced in sporangia,
usually on the underside of the leaves. (15 meters)
B. Have roots, leaves and stems. Usually narrow leaves (needles).
Male cones produce pollen while seeds will develop on the
surface of the scales of female cones. (100 meters)
C. Have roots, leaves, stems and flowers. Seeds develop inside
ovaries (part of the flower). Fruits develop from ovaries. (100
meters)
D. No roots but ‘root’ hairs called rhizoids. Simple
leaves/stems. Spores produced in capsules. (0.5
meters)
Animal Phyla
1.
2.
3.
4.
5.
6.
None of the animals in these phyla have a
backbone. They are invertebrates.
Porifera: Consists of sponges.
Cnidaria: Includes sea jellies (jellyfish) and coral
polyps.
Platyhelminthes: Includes the flatworms.
Annelida: Made up of segmented worms.
Mollusca: Includes snails, clams and octopuses.
Arthropoda: Includes insects, spiders and
crustaceans.
Key Features
Phylum and Examples
Porifera (Sponges)
Body Symmetry
No clear Symmetry
Features
Attached to a surface. Pores throughout body for diffusion. No
mouth or anus.
Platyhelminthes-Flatworms (Planaria,
Tapeworms, Liverflukes)
Bilaterally Symmetrical
Flat bodies. Unsegmented. Mouth but no anus.
Mollusca (Slugs, Snails, Clams,
Squids)
Bilaterally Symmetrical
Muscular foot and mantle. Shell usually present. Segmentation not
visible. Mouth and anus.
Cnidaria (Jellyfish, Corals, Sea
Anemones)
Radially Symmetrical
Tentacles. Stinging cells called nematocysts. Mouth but no anus.
Annelida (Earthworms, Leeches,
Ragworms)
Bilaterally Symmetrical
Bristles often present. Segmented. Mouth and anus.
Arthropoda (Insects, Spiders, Crabs,
Millipedes)
Bilaterally Symmetrical
Hard exoskeleton made of chitin. Segmented. Jointed appendages.
Radial vs. Bilateral Symmetry
Nematocysts
Self-Assessment
E. Bilaterally symmetrical, segmented,
exoskeleton, jointed appendages.
F. Bilaterally symmetrical, Flat bodies,
Unsegmented, Mouth but no anus.
G. Radially symmetrical, Tentacles, Stinging cells called
nematocysts, Mouth but no anus.
H. Bilaterally symmetrical, Bristles often present,
Segmented, Mouth and anus.
I. Muscular foot and mantle, Shell usually present,
Segmentation not visible, Mouth and anus.
J. No clear symmetry, Attached to its surface, Pores
throughout body, No mouth or anus.
Using and Making Dichotomous Key
How to Use a Dichotomous Key:
1. Look at the first section of the key which has a pair of sentences
describing a characteristic.
2. Look at the organism to see if the particular characteristic
described in the first line is present in the organism.
3. If the answer is ‘yes,’ go to the end of its line and find the
number of the next pair of statements to look at, follow the
number given and continue until the end.
4. If the answer was ‘no,’ go to the second statement just below
the first and that one should be true. Go to the end of its line
and find the number of the next pair of statements to look at,
follow the number given and continue until the end.
5. Keep going until the end of the line has a name instead of a
number—if you have answered each question correctly, that
will be the name of your organism.
A Simple Dichotomous Key
OR TRY
THIS ONE
Designing Your Own Dichotomous Key
LEARN HOW TO MAKE A
DICHOTOMOUS KEY HERE