1. Topic 5: Ecology and evolution
5.5 Classification
IB Biology SFP - Mark Polko

2. IB Biology SFP - Mark Polko
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.
IB Biology SFP - Mark Polko

3. IB Biology SFP - Mark Polko
5.5.1 Outline the binomial system of nomenclature.
The binomial system of nomenclature was designed by Carolus Linneaus, also known as Carl von Linné, in the 18th century. Linneaus’ idea is still the basis of the binomial system today. It is based on the idea that every species has a Latin name, made up of two parts.
The first part is the name of the genus, the second part specifies the species. The name should be printed in italics (or underlined when handwritten) and the first part (but not the second) is capitalised.
Some examples:
Humans - Homo sapiens
Domesticated dog - Canis lupus familiaris
Domesticated cat - Felis silvestris catus
Tiger - Panthera tigris
African elephant - Loxodonta africana
Iberian pear - Pyrus bourgaeana
IB Biology SFP - Mark Polko

4. IB Biology SFP - Mark Polko
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.
A kingdom is the largest group in the system of classification. A kingdom consists of one or more phyla (singular: phylum) which is divided into one or more classes, which is divided into one or more orders, which is divided into one or more families, which is divided into one or more genera (singular: genus), which is divided into one or more species.
IB Biology SFP - Mark Polko

5. IB Biology SFP - Mark Polko
5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta.
BRYOPHYTA
Mosses and liverworts small terrestrial plants do not have true roots, stems or leaves but they might have structures resembling them leaf-like structures are often arranged in a spiral usually live in clusters which act like sponges holding water.
IB Biology SFP - Mark Polko

6. IB Biology SFP - Mark Polko
5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta.
FILICINOPHYTA
Ferns
have true leaves
new leaves unroll
have an underground creeping stem (rhizome).
LINK
IB Biology SFP - Mark Polko

7. IB Biology SFP - Mark Polko
5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta.
CONIFEROPHYTA
Conifers
all conifers are woody plants, most are trees with a single wooden trunk with side branches
leaves are long thin needles, often arranged in spirals, often a dark green colour
produce seeds found in cones
IB Biology SFP - Mark Polko

8. IB Biology SFP - Mark Polko
5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta.
ANGIOSPERMOPHYTA
Flowering plants
They have flowers, although they may be small in windpollinated angiospermophyta
Seeds are in ovaries which become the fruit.
Leaves usually as leaf blade and leaf stalk, with veins visible on the lower surface.
IB Biology SFP - Mark Polko

9. IB Biology SFP - Mark Polko
5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.
PORIFERA
Sponges
most primitive animals with a simple body
live in water
do not move around
no mouth, but many small holes through which water is pumped into body
filter water for food and pump it out through larger holes
Just an illustration. No labelling needed
IB Biology SFP - Mark Polko

10. IB Biology SFP - Mark Polko
5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.
CNIDARIA
Jellyfish and sea anemones
have stinging cells (cnidocytes)
radially symmetrical
have a gastro-vascular cavity (hollow space in the centre of the body)
one opening to cavity
often have tentacles around the opening
Just an illustration. No examples are needed to know
IB Biology SFP - Mark Polko

11. IB Biology SFP - Mark Polko
5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.
PLATYHELMINTHES
Flatworms
soft flattened body, definite head region
bilateral symmetry
gastro-vascular cavity (hollow space in the centre of the body)
usually one opening to cavity
live in water or damp environment
can be free-living but often are parasitic
IB Biology SFP - Mark Polko

12. IB Biology SFP - Mark Polko
5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.
ANNELIDA
Worms and leeches
bodies of ring-like segments
have mouth and anus
live in water/moist earth
may be free-living or parasitic
no legs
bristles from body which help movement
Leech
IB Biology SFP - Mark Polko

13. IB Biology SFP - Mark Polko
5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.
MOLLUSCA
Snails, squids, clams, slugs
soft un-segmented bodies
may have shell
IB Biology SFP - Mark Polko

14. IB Biology SFP - Mark Polko
5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.
ARTHROPODA
Animals with jointed legs
exoskeleton made of chitin (a polysaccharide)
segmented body
appendages to each segment
at least 3 pairs of jointed legs
many free-living but also some parasitic
IB Biology SFP - Mark Polko

15. IB Biology SFP - Mark Polko
5.5.5 Apply and design a key for a group of up to eight organisms.
In Biology, a key is used to identify an organism. Imagine that you are taking someone to a farm who does not know the appearance of a cow, a horse, a chicken or a pig. You could give this person the following key:
1. Animal is taller than 1.5 metres go to 2
Animal is smaller than 1.5 metres go to 3
2. Animal is black and white cow
Animal is brown horse
3. Animal has feathers chicken
Animal is pink with curly tail pig
You can make a key to identify items of any group of things. If there are two choices at each stage it is called a dichotomous key. The important thing is that it works. In Biology, keys are most commonly used to identify plants, insects and birds. These are often area specific, for example, the Plants of Northern Europe.
IB Biology SFP - Mark Polko

16. IB Biology SFP - Mark Polko
Example of a dichotomous key
IB Biology SFP - Mark Polko

17. Topic 5: Ecology and evolution
5.4 Classification
IB Biology SFP - Mark Polko