IGCSE Biology Core Chapter 1 Characteristics & classification of living things

1. Classification
of living things
Y9 Core Biology

2. Characteristics of living things
 Movement
 Respiration
 Sensitivity/Irritability
 Growth
 Reproduction
 Excretion
 Nutrition

3. Characteristic Definition
The ability to change position of part or all the body
The break down of food molecules inside living cells to
release energy
The ability to sense and respond to changes in the internal
or external environment.
The permanent increase in (dry) mass, size and/or
number of cells.
The ability to produce organisms of the same kind.
The removal of metabolic wastes, toxic molecules and
substances in excess of requirement from the body
Taking in substances needed for growth, respiration and
repair.
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition

4. Why do we need to classify
living things?
 There are over 1.4 million different species of
discovered organisms on earth. We classify
them to make studying them easier.
 Organisms are divided into five large groups
called kingdoms.

5. kingdoms
animals plants fungi protoctists Bacteria

6. Animals

7. Plants

8. Bacteria

9. Fungi
Yeast
Mucor

10. Protoctists
Amoeba
Euglena
Paramecium
Chlorella
Plasmodium

11.  We still find that in each group there may be
organisms that are very different such as ants and
giraffes in the animal kingdom.
 That is why each kingdom is divides into smaller groups
called phyla (singular: phylum).
 Each phylum is divided into several classes, then a class is
divide into orders, then family, then genus and finally the
smallest group is called species.
 Kingdom>phylum>class>order>family>genus>species.
 Try to remember them using this sentence:
 King Philip cut oranges for good students.

12. Animal kingdom
 Animals are either vertebrates (have a back
bone) or invertebrate (without a back bone).
 Vertebrates are divided into five classes.

13. vertebrates
Fish Amphibians
Reptiles
Bird
s
Mammals

14. Fish Amphibians Reptiles Birds Mammals
Body covering
Limbs
Ears
Eggs
Other
features

15. Fish Amphibians Reptiles Birds Mammals
Body
covering
Moist scales Moist,
smooth skin
Dry and
rough scales
Feathers on
body, scales
on legs
Hair/ fur or
whiskers
Limbs Fins instead
of limbs
Young: fins
Adult: 4
limbs
4 limbs 4 Limbs
(2 wings, 2
legs)
4 limbs
Ears
lateral line
that feels
vibrations
Eardrum on
the surface
of the skin
A hole
leading to
the
eardrum
A hole
leading to
the
eardrum
An external
ear
Eggs
Lay eggs in
the water
covered
with jelly
Lay eggs in
the water
covered
with jelly
Lay eggs on
land with
rubbery
shells
Lay eggs on
land with
hard shells
Give birth
to their
young

18. Insects Arachnids Crustaceans Myriapods
Body segments
Number of legs
Antenna
Other features
Common features They all have: 1. Segmented bodies 2. Jointed legs 3. A hard exoskeleton

19. Insects Arachnids Crustaceans Myriapods
Body segments 3 body
segments
2 body
segments
2 body
segments
Many body
segments
Number of legs 3 pairs of legs 4 pairs of legs More than 4
pairs of legs
Many pairs of
legs
Antenna 1 pair none 2 pairs 1 pair
Other features Some have
wings
Some have
poisonous
glands
Some have a
very hard
exoskeleton
None
Common features They all have: 1. Segmented bodies 2. Jointed legs 3. A hard exoskeleton

21. Compound
eyes help
some
arthropods to
see in low
light
intensities
and can easily
spot
movement.

22. Molting in insects

23. Ch1 Checklist
 1.1 Characteristics of living organisms
1. Describe the characteristics of living organisms by defining the terms:
a) movement as an action by an organism causing a change of position or place
b) respiration as the chemical reactions in cells that break down nutrient molecules and release energy for
metabolism
c) sensitivity as the ability to detect and respond to changes in the in the internal or external environment
d) growth as a permanent increase in size and dry mass
e) reproduction as the processes that make more of the same kind of organism
f) excretion as removal from organisms of waste products of metabolism and substances in excess of
requirements
g) nutrition as taking in of materials for energy, growth and development
 1.2 Concept and use of a classification system
1. State that organisms can be classified into groups by the features that they share
2. Describe species as a group of organisms that can reproduce to produce fertile offspring
3. Describe and describe the binomial system of naming species as an internationally agreed system in which
the scientific name of an organism is made up of two parts showing the genus and species
4. Construct & use dichotomous keys based on identifiable features
 1.3 Features of organisms
1. State the main features used to place animals and plants into the appropriate kingdoms
2. State the main features used to place organisms into groups within the animal kingdom, limited to:
 – main groups of vertebrates: mammals, birds, reptiles, amphibians, fish
– the main groups of arthropods: myriapods, insects, arachnids, crustaceans
3. Classify organisms using their features identified in 1.3.1 & 1.3.2