22
How do we classify vertebrate animals?
Living things
What are the characteristics of mammals?
Vertebrates are multicellular animals that have a spinal column.
They are classified into five groups: mammals, reptiles, fish,
birds and amphibians. Invertebrates are multicellular
animals too, but they don’t have a spinal column.
1
Which photo shows a vertebrate? Which shows an invertebrate?
How do you know?
a)
b)
Photo ... shows a/an … because I can/can’t see …
G
E T T I N G S T A R T E D
Extremities
Most terrestrial mammals have
four legs, but human beings have
two legs and two arms. Aquatic
mammals, such as whales and
dolphins, have fins for swimming.
Many terrestrial mammals also
have a tail.
Respiration
All mammals have
lungs
to breathe air.
Mammals’ bodies
Skin and hair cover mammals’
bodies. In some animals, the
hair is thick and called
fur
.
Reproduction
Almost all mammals are
viviparous
. This means
that female mammals give birth to live young.
They produce milk to feed their young.
The smallest vertebrate
is a frog called the
Paedophryne amauensis
.
It is only about 1 cm long!
S
C
I
-
F
A
C
T
