1.Characteristics and classification of
living organisms
Characteristics of living things
1. Movement
2. Respiration
3.Sensitivity
4. Growth
5. Reproduction
 Sexual - two sex cells
required (sperm and egg)
 Asexual - only one
parent cell is needed
6. Excretion
7. Nutrition
 Autotrophs - get energy from
sun
 Heterotrophs - get energy by
consuming nutrients from their
environment
Concept and use of a
classification system
WHY DO WE CLASSIFY THINGS?
List some places where
organization/ classification
takes place
What is classification?
 Classification: arranging organisms into orderly groups
based on similar characteristics
 Taxonomy: the science of describing, naming, and
classifying organisms
 Scientists use both genetic (the DNA makeup of a living
thing) and physical evidence (how it looks) to classifying
living things.
Natural classification
The hierarchical classification system described above is
based on
a natural classification system that uses common features
shared
by organisms. Natural classification is based on two ideas:
• similar structures- (Morphology & anatomy)
• evolutionary relationships
Early classification
 Aristotle grouped everything into
simple groups such as animals or plants
 He then grouped animals according to if they had
blood or didn’t have blood, and if they had live young
or laid eggs, and so on…
Therefore
 Organisms can be classified into
groups by the features that they share
 They were classified based on morphology and anatomy
Concerned with the
identification and
description of the
body structures of
living things
Binomial Nomenclature
 Developed by Carolus
Linnaeus
 Swedish Biologist 1700’s
 Two-name system
 Genus and species named
using Latin or Greek words
The Binomial System
Rules used to write scientific names
The scientific name
Species: group of individualslook alike, live in same habitat,
breed together producing fertile
offspring
Genus: group of individuals
closely related, but cannot
interbreed
Task
Write down the scientific name of the following
organisms
e.g.
• Dog
• cat,
• Cow
• Rat
• Monkey
• Red rose.
Classification systems aim to
reflect evolutionary relationships
Classification and cladistics
Sequence of bases in DNA and of amino acids in proteins is a more
accurate means of classification.
The organisms may be different morphologically, however, their
DNA and amino acid sequences may be similar.
e.g mice and humans were found to share virtually the same set of
genes after studying their base sequences. However, they are
physically different.
Cladistics also allows to to determine
evolutionary relationship of organisms. By
sequencing the DNA and amino acid bases of
organism, similar base sequences can be
determined. More recent ancestors (more
closely related ones) have base sequences
that are more similar than those that share
only a distant ancestor.
From the diagram above: Determine
The most recent ancestorsThe distant ancestors-
Classification systems aim to
reflect evolutionary relationships
1.3 Features of Organisms
The modern system of classification has 8
levels:
Domain
Order
Kingdom
Family
Phylum
Genus
Class
Species
Now, let’s play with the words and see if we can
think of any rhymes to help us remember each
classification word.
Kingdom–
Phylum –
Class –
Order –
Family –
Genus –
Species –
- King, kings, kids, any k words....
- play, Phillip, party
- chess, checkers, cooks, came
- on, over
- for, fine, fun
- glass, great
- spaghetti, sets
Obviously, different people may come up with different sentences or
rhymes that help them. For today, let’s go with:
KINGS PLAY CHESS
ON FINE GLASS SET
Helpful way to remember the 7 levels
Kids playing catch on freeways get squashed
 Or…make up your own…

KPCOFGS
The five Kingdoms
Characteristics of different kingdoms
Kingdom
Animalia
Plantae
Fungi
Protoctista
Prokaryotes
Characteristics and Examples
Vertebrates
Feature
1. Body
2. Habitat
3. Feeding
habits
4. Fertilisation
5. Breathing
6. Blood
7. Movement
8. Examples
Fish
Amphibians
Reptiles
Birds
Mammals
Invertebrates-Arthropods
Feature
1. Body
2. Habitat
3. Feeding habits
4. Eyes
5. Breathing
6. Movement
7. Examples
Fish
Amphibians
Reptiles
Birds
Mammals
Structure of a virus
Scientists do not
classify a virus as a
living thing. This is
because:
•it does not show all
seven processes for
life
•when it enters a cell
it changes the way a
cell works so it can
make copies of the
virus.
Classification
of plants
M
Types of seeds
Dicotyledon
Monocotyledon
Artificial classification-Dichotomous key
With artificial classification you can use any grouping you like.
You could put all the animals that fly in the same group. This
group would then include birds, bats and many insects. You could
put all animals that live in water and have streamlined, fish-like
bodies in the same group. This group would then include fish and
whales.
Artificial classification systems are also used as the basis for
dichotomous keys that biologists use to identify organisms.
A dichotomous key is an organized set of pairs of mutually exclusive
characteristics of biological organisms.
Taxonomic Key
 1a Fruits occur singly ................................................. Go to 3
 1b Fruits occur in clusters of two or more ................ Go to 2
 2a Fruits are round ................................................... Grapes
 2b Fruits are elongate ............................................... Bananas
 3a Thick skin that separates easily from flesh .........Oranges
 3b Thin skin that adheres to flesh .............................. Go to 4
 4a More than one seed per fruit ............................ Apples
 4b One seed per fruit ............................................ Go to 5
 5a Skin covered with fuzz.................... Peaches
 5b Skin smooth, without fuzz........................... Plums
What steps would you use to identify an apple?