01 CHARACTERISTICS & CLASSIFICATION OF LIVING ORGANISMS

INVERTEBRATES - NEMATODE

Examples: Hookworm
Body: Long, thin body, soft, not waterproof
Body covering: Covered with mucus to resist attack by host’s digestive
juice
Are body segments visible?: NO
Movement: Live in one place but wriggles (using its long muscles)
Feeding method: Mainly parasites (in gut of other animal)
Mouth: Sucking (blood)

INVERTEBRATES - MOLLUSC

Examples: Snail, octopus, squid, oyster, abalone, clams, mussels, cockles
Body: Soft
Body covering: Covered with a shell, to protect body from predators &
drying out (mostly)
Are body segments visible?: NO
Movement: Creeps on foot to move
Feeding method: Mainly herbivores, some carnivores
Mouth: Scraping

INVERTEBRATES - ARTHROPOD

Most numerous of all animals
Common criteria of all arthropods

Have hard skeleton (exoskeleton) on the outside of their
body

Jointed legs/limbs
Segmented body (3 segments: Head, Thorax, Abdomen)



ARTHROPOD

4 Classes of arthropod
Insect
Crustacean
Myriapod
Arachnid

ARTHROPOD - INSECT

Examples: Fly, mosquito, bee, ant
Body segment: 3 segments (head, thorax, abdomen)

Legs/limbs: 3 pairs
Eyes: Compound eyes
Antennae: A pair
Uniqueness:

 1 or 2 pairs of wing
 Metamorphosis: change of body form, to allow use of resources of their habitat
to the maximum

METAMORPHOSIS

Butterfly
Dragonfly

ARTHROPOD - CRUSTACEAN

Examples: Crab, shrimp, prawn,
lobster
Body segment: Often 2 segments
(head & thorax combined, abdomen)
Legs/limbs: 5 or more pairs, some
may be modified to claws
Eyes: Compound eyes
Antennae: A pair

ARTHROPOD - CRUSTACEAN

Uniqueness:

Have Carapace; thick, hardened shell
Have gills under shell for uptake of
oxygen in water
Molting (change of shell)

ARTHROPOD - MYRIAPOD

Examples: Centipedes, milipedes
Body segment: Many segments (head, intermediate segments
and tail)
Legs/limbs: 1 or 2 pairs/ segment
Eyes: Simple eyes
Antennae: A pair
Uniqueness: Waterproof body covering

ARTHROPOD - ARACHNID

 Examples: Spider, scorpion, mites
Body segment: 2 segments (head & thorax combined, abdomen)
Legs/limbs: 4 pairs (8 legs)
Eyes: Multiple simple eyes
Antennae: None
Uniqueness:

 Mostly poisonous
 All spiders are predators
 Have powerful, piercing jaws

VERTEBRATE

5 groups of vertebrates:
1. Fish
2. Amphibian
3. Reptile
4. Bird
5. Mammal

BLOOD TEMPERATURE

Poikilothermic: An organism which having a body
temperature that varies with the temperature of the
surroundings (cold-blooded)
Homeothermic: An organism which having a constant
body temperature maintained through thermal homeostasis
(warm-blooded)

FERTILISATION

Internal fertilisation: Fertilisation occurs inside female’s
body

External fertilization: Fertilisation occurs outside female’s
body

VERTEBRATE - FISH

Body coverings: Wet scales
Movement: Fins for swimming
Reproduction: Mostly external fertilization, eggs in water
Sense organs: Eyes
Body temperature: Poikilothermic (cold-blooded)
Others: Gills for breathing underwater

VERTEBRATE - AMPHIBIAN

Examples: Frog, toad
Body coverings: Moist, smooth skin
Movement: 4 limbs, webbed back limbs for
walking and swimming
Reproduction: Mostly external fertilization, no-shell eggs in water
Sense organs: Eyes & ears
Body temperature: Poikilothermic (cold-blooded)

VERTEBRATE - AMPHIBIAN

Others:
• Part aquatic, part terrestrial
• Molting (change of skin)

QUESTION

What is two similarities between fish and amphibians?

QUESTION

What is two similarities between fish and amphibians?
• External fertilization
• Poikilothermic (cold-blooded)

VERTEBRATE - REPTILE

Examples: Crocodile, lizard, snakes,
turtle, tortoise

Body coverings: Dry, scaly skin

Movement: 4 limbs (except snake) for
crawling and climbing

Reproduction: Internal fertilization,
soft-shelled eggs on land
Sense organs: Eyes & ears
Body temperature: Poikilothermic (cold-blooded)

VERTEBRATE - REPTILE

Others:
•Tail can be used for
swimming
•Molting (change of skin)

QUESTION

What is the difference between fish and reptiles in terms
of body covering?

QUESTION

What is the difference between fish and reptiles in terms
of body covering?

• Fish has wet scales
• Reptiles have dry scaly skin

VERTEBRATE - BIRD

Body coverings: Feathers, scales on legs, beak
Movement: Wings for flying, 2 legs
Reproduction: Internal fertilization, hard-shelled eggs
Sense organs: Eyes & ears
Body temperature: Homeothermic (warm-blooded)

VERTEBRATE – MAMMAL

Body coverings: Fur/hair
Movement: 4 limbs for walking and climbing
Reproduction: Internal fertilization and internally developed
embryo
Sense organs: Eyes & ears
Body temperature: Homeothermic (warm-blooded)
Other: Mammary glands to produce milk

QUESTION

1. What is the difference between eggs produced by
amphibians, reptiles and birds?

2. What is the difference between birds and mammals in
terms of body covering?

QUESTION

1. What is the difference between eggs produced by
amphibians, reptiles and birds?

• Amphians have no-shell eggs in water
• Reptiles have soft-shelled eggs
• Birds have hard-shelled eggs

QUESTION

2. What is the difference between birds and mammals in
terms of body covering?

• Birds are covered by feathers
• Mammals are covered with fur/hair

The End