01 CHARACTERISTICS & CLASSIFICATION OF LIVING ORGANISMS

CHARACTERISTICS & CLASSIFICATION
OF LIVING ORGANISMS

What is BIOLOGY?





LIVING ORGANISM

MRS GREN

LIVING ORGANISM

•M- Movement
•R- Respiration
•S- Sensitivity
•G- Growth
•R- Reproduction
•E- Excretion
•N- Nutrition



LIVING ORGANISM

Movement  Change in place of an organism or a part of it

 animals move to hunt
 plants move towards light

Respiration  Chemical reaction that breaks down nutrients to
release energy for metabolism

 All the chemical reactions going on within a living organism, that keep a cell alive

Sensitivity  Ability to detect and respond to stimuli in the external
or internal environment

LIVING ORGANISM

Growth  Permanent increase in size and dry mass by an increase in
cell numbers, cell size, or both

Reproduction  Process that makes more of the same kind of
organism

Excretion  Removal of waste products, toxic materials, and
substances in excess from the body

Nutrition  Intake of materials for energy, growth, and development

LIVING ORGANISM

•M- Movement
•R- Respiration
•S- Sensitivity
•G- Growth
•R- Reproduction
•E- Excretion
•N- Nutrition

CLASSIFICATION

The science of placing organisms into categories on
the basis of their observable characteristics



5 MAIN KINGDOMS EUKARYOTES

PROKARYOTE
PROTOCTISTANT
PLANT
ANIMAL
FUNGI

Prokaryotes All living organisms More than one cell

A definite nucleus? YES NO

NO YES Protoctistants

Heterotroph

YES NO

Cell wall & external digestion Plants

YES NO

Fungus Animals

Definite nucleus: A
nucleus that is surrounded
by a layer called
membrane (bound
membrane)
Prokaryotes: Organisms
without definite nucleus
(free DNA)
Eukaryotes: Organisms
with definite nucleus

Prokaryotes All living organisms More than one cell

A definite nucleus? YES NO

NO YES Protoctistants

Heterotroph

YES NO

Cell wall & external digestion Plants

YES NO

Fungus Animals

PROKARYOTES

High temperature

An acidic
mud pot

Prokaryotes All living organisms More than one cell

A definite nucleus? YES NO

NO YES Protoctistants

Heterotroph

YES NO

Cell wall & external digestion Plants

YES NO

Fungus Animals

PROTOCTISTANT

Protozoa (animal-like)
Single-celled algae (plant-like)

Largest single-celled organism on earth, bubble algae!

Slime mold (fungi-like)

Parasites
Dog vomit slime mold

Prokaryotes All living organisms More than one cell

A definite nucleus? YES NO

NO YES Protoctistants

Heterotroph

YES NO

Cell wall & external digestion Plants

YES NO

Fungus Animals

TERMS YOU NEED TO KNOW

Autotroph: An organism capable of making its own food from inorganic
substances, using light or chemical energy.
Heterotroph: An organism that obtains food by feeding on other organisms,
e.g. animals, fungi.
External digestion: Food is digested outside the organism’s body by secreting
enzymes that degrade the food, and then absorbed through diffusion.
Cell wall: A rigid layer protecting a cell

FUNGI

A decomposer
Some are parasites
Have an external digestion

WHY CLASSIFICATION IS IMPORTANT?

To study morphology and anatomy (shape, structure and
characteristics)

 Organisms can be classified into groups by the features they share

To identify organisms that share a more recent ancestor are more
closely related than those that share only a distant ancestor

 Determined by DNA sequences and amino acids in protein

To reflect evolutionary relationship

VIRUS

Is a virus
living

organism?

VIRUS

Not classified as an organism
because they do not show the 7
characteristics unless they are in
cells
They act as parasites
Most viruses cause disease by
infecting humans/domestic
animals/plants

Virus infection

Has common structure

Protein coat
Genetic information (DNA/RNA)

HIERARCHY OF CLASSIFICATION

Kingdom
Phylum
Class
Order
Family
Genus
Species
King Philips Came Over For a Great Sandwich

BINOMIAL NOMENCLATURE

 Species naming system
 An internationally agreed system in

which the scientific name of an
organism
 Name is made up of two parts
showing the genus and species
(Genus species)
 For example; Homo Sapien



PLANTS

PLANTS

All plants are autotroph

Able to make their own food, through photosynthesis

Photosynthesis

Occur in chloroplast
Use light-energy
Main component: chlorophyll (light-absorbing pigments)

They have cell walls that are made of cellulose

4 GROUPS OF PLANTS

1. Algae
2. Moss
3. Fern
4. Angiosperm (flowering plant)



ALGAE

MOSS

As plants evolve from life in the water to land,
ferns and angiosperms are better at
adapted to life on land

FERN

Young frond

Stem

Simple, true
roots

FERN

ANGIOSPERM

Flowering plants, produced by seeds
Most successful plants, 80% of all
plants

COTYLEDON

Angiosperms have seeds which contain
cotyledon

Cotyledon: An embryonic leaf in
seed-bearing plants, one or more of
which are the first leaves to appear
from a germinating seed.

video

ANGIOSPERM Monocotyledon Dicotyledon

2 Groups

Monocotyledons

 One cotyledon
 Matured leaf, parallel vein
 Elements of flowers in multiple of 3 or 4 (i.e. 3 stamen,

6 petals)

Dicotyledons

 Two cotyledons
 Matured leaf, branched vein
 Elements of flowers in multiple of 5 (i.e. 5 stamen, 5

petals)

ANGIOSPERM

ANGIOSPERM Dicotyledon

Monocotyledon

IN SUMMARY

4 main phylums of plants

IN SUMMARY…

QUESTIONS

• In what ways are ferns well adapted to the life on
land?

ANIMALS

2 main groups of Animals
 Vertebrate (with back bone)
Invertebrate (without back bone)



ANIMALS

INVERTEBRATES

4 Groups of invertebrate Animals
Annelid
Nematode
Mollusc
Arthropod

INVERTEBRATES - ANNELID

Examples: Earthworm
Body: Long, cylindrical, hard, slightly waterproof
Body covering: Covered with mucus layer to stop drying out
Are body segments visible?: YES
Movement: Use chaetae (bristles) to move
Feeding method: Herbivores
Mouth: Can bite of pieces