1. 5.5: Classification Pp

2. Binomial system of nomenclature
System of assigning scientific/binomial names to organisms designed by Carolus Linneaus in 18th century
Based on idea that every species has a Latin name, made up of two parts
First part is the name of the genus
Second part specifies the species
Name should be printed in italics (underlined if hand written) and first part capitalized
Example: Binomial name for Humans is Homo sapiens

3. Hierarchy of Taxa Taxonomy is the study of classification
Organisms are placed in groups based on similarities & differences
Organisms that share characteristics are placed into similar groups
The more similar their characteristics, the closer the grouping
Taxon (plural: taxa)is a group/unit in a classification system
There are seven taxonomic units:
Kingdom
Phylum
Order
Family
Genus
Species

6. Kingdom Plantae Phylum Filicinophyta Phylum Bryophyta Phylum
Angiospermohyta
Phylum
Coniferohyta

7. Plant Phyla Kingdom: Plantae Characteristics:
Photosynthetic
Chlorophyll
Cellulose cell wall
Permanent vacuoles
Stores starch
Classification of the major plant phyla is based on external observables structures

8. Using external recognition features only, distinguish between the following phyla of kingdom plantae: bryophyta, fillicinophyata, coniferophyta & angiospermophyta

9. Need to know: -Bryophyta -angiospermophyta
-Filicinophyta -Coniferophyta

10. Phylum: Bryophyta (Mosses, Liverworts, Hornworts)
Small terrestrial plants
Do not have true roots, stems or leaves but they must have structures resembling them
Leaf-like structures are often arranged in a spiral
Usually have live in clusters which act like sponges holding water
No cuticle
Reproductive structures are called sporangium which is on long stalks with capsules on end.

11. Phylum: Filicinophyta (ferns)
Have true leaves in fronds
New leaves unroll
Divided leaves
There is cuticle on leaves
Have an underground creeping stem (rhizome)
Height up to 20m but not woody
Reproduction: sporangia (sori) contain reproductive spores

12. Phylum: Coniferophytes (conifers & pines)
All conifers are woody plants, most are trees with a single wooden trunk with side branches
Differentiated into; roots, stem & leaves
Leaves are waxy, long thin needles, often arranged in spirals, often a dark green colour
Stem & roots are woody
Produce naked seeds found in cones
Vascular system (tracheids)

13. Phylum: Angiospermophyta (flowering plants and grasses)
Differentiated into roots, stem, leaves & flowers
Have flowers, although they may be small in wind-pollinated angiospermophyta
Seeds produced in ovaries which become the fruit
Leaves usually as leaf blade and leaf stalk, with veins visible on the lower surface
Leaves have waxy cuticle
Vascular bundles (veins) are made
up of xylem & phloem

14. Animal phyla Heterotrophic No cell walls No vacuoles No chlorophyll
The kingdom of animals is classified according to these characteristics:
Heterotrophic
No cell walls
No vacuoles
No chlorophyll
Store glycogen

15. Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.

16. The six phyla are classified according to features such as:
The syllabus specifies 6 of the 30 or more phyla from the animal kingdom that you are responsible for knowing
The ones selected are what might be called invertebrates (lack of a spinal cord)
The six phyla are classified according to features such as:
Number of layers in the body parts
The opening for mouth and anus
Method of support
Phylogenic studies (evolutionary relationship) relies on more genetic studies to support the modern classification of these groups.

17. Phylum: Porifera (sponges)
no clear symmetry
No body layer, rather there is an aggregate of different cell types
Support is from either silica or calcium based spicules which link together to provide some support i.e. they are attached to a surface
Body plan is built around water canals that circulate nutrients through the sponge for ingestion by specialized cells
There is no mouth or anus

18. Phylum: Cnidaria (Jelly fish, Sea anemones, Corals)
Body has radial symmetry
They have two layers in the body plan
Jelly fish are mobile organisms. Sea anemones are sessile organisms
Single entrance that serves the cavity & functions as circulation of respiratory gases and nutrients i.e. they have mouth but no anus
Have tentacles & stinging cells
These organisms are secondary consumers and posses stinging cells with toxins called nematocysts to disable prey
Corals secrete a CaCO3 skeleton

19. Phylum: Platyhelminthes (flatworms)
3 layers in the body plan
bilateral symmetry
unsegmented, flat body
One entrance to “gut” which can have many folds to increase surface area i.e. have mouth, but no anus
Largely parasitic, includes flukes

20. Phylum: Annelida (segment worms)
3 layers to the body plan
Bilateral symmetry
Body is divided into ringed segments with some specialization of segments
Mouth is connected via gut to a separate anus
Skin surface is used for gas exchange
Many marine forms but also terrestrial species, usually soil burrowing

21. Phylum: Mollusca (Snails, Slugs, Octopus)
Bilateral symmetry with significant modification
Have mouth and anus
Body plan has three major features
Foot, a muscular structure used for movement and burrowing
Central visceral mass, contains all the organ structures (separate mouth & anus)
Mantle, a folded membrane structure that can surround other tissues and create a cavity containing gill. The mantle frequently secretes a calcareous shell.

22. Phylum: Arthropoda (Insects, Crustaceans, Spiders, Scorpions, Millipedes)
3 layer body plant with bilateral symmetry
Hard exoskeleton composed of chitin
Jointed body segments
Jointed appendages to each segment
At least 3 pairs of jointed legs
Some flying organisms in the class Insecta
Separate mouth and anus
Many free-living but also some parasitic

23. Dichotomous Keys
Each questions divides the group of organisms into two smaller groups based on a pair of alternative characteristics
Subsequent groups may focus on more minor details
In most cases the characteristic will be readily observed or measurable
It is better to choose characteristics that are uninfluenced by environmental variation
Shape and number are often good characteristics on which to base alternative pairings
A complete key will have each type of organisms being classified separated with a final identifying name

24. Revision Questions Outline the binomial system of nomenclature.
List down the seven levels in the hierarchy of taxa.
Using simple external recognition features, distinguish between the following phyla of kingdom plantae: bryophyta, filicinophyta, coniferophyta and angiospermophyta.
Using simple external recognition features, distinguish between the following phyla of kingdom animalia: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.

25. Using observable characteristics only, design a dichotomous key for identifying the following arthropods.