The document discusses the classification of living things, describing how Aristotle was one of the first to classify organisms into groups based on their characteristics. It explains that today Carolus Linnaeus' system of binomial nomenclature, which assigns every species a two-part scientific name, is still used. The document also outlines the five kingdom system of classification and provides examples of how dichotomous keys can be used to classify organisms based on distinguishing characteristics.

1. CLASSIFICATION
of
living things

2. Individual, pair and share
First, answer this question on
your own and then discuss it
with your partner, and then with
your class!
3
mins
What does classification mean?
Why is it important?

3. Why Classify?
Classifying is sorting organisms into groups.
Classifying helps with:
◦ Identifying Organisms:
◦ Makes it easier to find out which species an organism belongs
◦ Evolutionary Links:
◦ Provides information that can be used to predict how organisms evolved.
Species of the same genus share characteristics which mean they probably
evolved from a common ancestor.
◦ Prediction of Characteristics
◦ Allows you to predict the characteristics of other organisms in similar groups

4. What do we Classify?
Examples of classification;
Stamps
Coins
Library
Clothes
Animals/Plants
Supermarket

5. The Greek thinker Aristotle was one of the first
people to sort organisms into groups based upon their
characteristics (what they look like). This is called
classification.
Today scientists have classified over 1.75 million
different living things.
Aristotle

6. Father of Taxonomy- Carolus Linnaeus
Classified about 12,000 organisms
into groups based on similar
characteristic.
His basic system is still used today.
Science of classifying things
using this method is called
“Taxonomy”.

7. The Binominal System of
Nomenclature
Each species needs a name so that biologists
around the world can refer to it.
Naming of species is called Nomenclature.
Biologists use the Binomial System
(developed by Carl Linnaeus 1707-1778)
◦ Two names are used to refer to each species

8. The Binominal System of
Nomenclature
Features of the Binomial System are:
◦ First name is the genus name (uppercase 1st letter)
◦ Second name is the species name (lowercase 1st letter)
◦ Genus and species are usually printed in italics or
written and underlined
e.g: Homo sapiens, Felis tigris

9. Classification…
We classify organisms in a system known as a phylogenetic hierarchy
Organisms are placed into groups based on their increasing similarities
Kingdom
Phylum (pl. phyla)
Class
Order
Family
Genus (pl. genera)
Species
Increasing
similarity between
organisms
Increasing number of
species
Kings
Play
Cards
On
Fat
Green
Stools

10. The Five Kingdom System

11. The Five Kingdom System
Taxonomists do not always agree about how living organisms should be classified.
A widely used system for classifying has 5 kingdoms:
◦ Animals – Animalia
◦ Fish, Mammals, Birds, Reptiles, Amphibians, Insects, Molluscs
◦ Plants – Plantae
◦ Algae, Ferns, Conifers, Moses and Liverworts, Angiosperms
◦ Fungi
◦ Moulds and yeasts
◦ Protists- Protoctista
◦ Unicellular organisms eg: Amoeba, Paramecium
◦ Monera– Prokaryotae
◦ Bacteria
(Remember there is still debate over whether Viruses are considered living)

13. PLANTS

14. Classifying humans
Kingdom Animalia Multicellular organisms, cells have
no cell walls.
Phylum Chordata Animals with backbones
Class Mammalia Hairy skins, produce milk to feed their
young
Order Primates Flat faces, forward facing eyes,
opposable digits.
Family Hominidae Human-like creatures
Genus Homo Humans are the only living member of
this genus
Species sapiens All modern humans belong to this
species

15. What is a Key and why use it?
A KEY uses features of animals and plants that are
easily seen and set in a way to identify them.
KEY is really a list of clues.
Each clue tells us something about the structure of
the ‘object’ being identified.

16. Method of Classification
One method involves using dichotomous keys for
classification.
This method allows an organism to be classified using a
choice of two characteristics at each level.
There are two types of keys used.

17. A Dichotomous Key
Divides each clue into TWO distinct parts.
All buttons
Metal Non-metal
Round Other shapes Non-white White
2 holes 4 holes 4 holes
Button C
Button A
Button B Button F
2 holes
Button D Button E

18. Use the first key below to sort or classify the little green
aliens into four separate groups. Identify the alien that fits
into each spaceship.

19. no hair hair
curly
hair
straight
hair
no toestoes

20. 1. a metal buttons ............................................... Go to 2
b non-metal buttons ....................................... Go to 4
2. a round shape................................................. Go to 3
b other shapes ............................................... BUTTON C
3. a two holes .................................................... BUTTON A
b four holes ................................................... BUTTON B
4. a white .......................................................... BUTTON D
b non-white .................................................. Go to 5
5. a two holes ..................................................... BUTTON F
b four holes .................................................... BUTTON E
Button E
Button D
Button F
Button AButton B Button C

21. 1. a hair present .................................................Go to 2
b no hair present............................................ ALIEN 4
2. a ears present ............................................... Go to 3
b no ears present .......................................... ALIEN 2
3. a toes present................................................ ALIEN 3
b no toes present........................................... ALIEN 1

22. TRY ONE YOURSELF
A Grocer’s Shop Key
Make two keys to classify the grocery items below.
You need to use both method to classify these items.
canned pumpkin soup block of cheese
frozen beans Smiths potato chips
butter chocolate ice cream
baked beans milk
bacon canned asparagus
yoghurt sardines
bread orange juice

23. TRY ONE YOURSELF
Design a dichotomous key to classify the different types of apparatus