Transcript animals classification

ANIMAL CLASSIFICATION
Animals evolved from colonial flagellated
protists as a result of division of labour
among colonial cells.
Coordination of specialized cells with other group
of cells begun and more complex organism are
evolved. They are called animals.
Animals are;
• Multicellular eukaryotes
• heterotrophs
• Sense food source
• Ingestion (eating food – distinctive feature of animals)
• No cell wall
• Digest food within the body
• Most of them have embryonic layers (these layers form
tissues, organs, systems)
• Cells are connected to eachother by extracellular
proteins (connective tissue)
• Most animals have diploid life cycle
• Most animals have muscle tissue for movement, nerve
for impulses.
Animals are divided into two groups
according to their body symmetry
1) Radial symmetry has one main axis
around which its body parts are
arranged. (Simple sponges, sea
anemones, Cnideria have radial
symmetry). These animals move
slowly or not at all.
2) Bilateral symmetry is a common
characteristic of animals that move
rapidly through their
environments(active animals). They
can be divided into mirror images.
There is cephalization in bilateral
symmetry. Sensory organs are
located on the head.
Animals can be divided into three main
groups according to their body cavity.
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Acoelomates: lack of enclosed body cavity
Pseudocoelomates: have body cavity a liquid filled space in
which many of the internal organs are suspended. There is
only outer muscle layer and there is no inner layer of
muscle surrounding organs.
Coelomate: have a body cavity. It is enclosed by both inner
and outer muscle layers
Fluid filled body cavity gives the animal better
control over its movement. ( Movement of heart,
stomach )
Brief Classification of Animals
1) Phylum porifera
• Simplest animals
• They have pores in their structure, so all
cells have contact with environment
• There are no systems in their structure
• They are suspension feeders (filter
feeders). They collect food particles when
water passes through the pores.
• Sessile organisms
2) Phylum Cnideria(coelenterates)
• They have two layers of cells, so all cells have
contact with environment. They can be in two
forms polyp or medusa.
• They have a body cavity with single opening.
Tentacles catch the prey and they digest.
• They have radial symmetry. They have simple
nerve net and muscle cells.
• Tentacles have stinging cells that penetrate and
paralyze the prey.
• e.g: jelly fish (motile), hydra (sessile)
3) Phylum Platyhelminthes
• They are bilateral leaf like (flat) animals. There
are more than three layers of cells. They have
incomplete digestive tract with single opening.
• There is no space between digestive tract and
outer layer (no coelom). They have simple
nervous and excretory system.
• Non-parasitic flatworms live in marine, fresh
water damp soil in terrestrial ecosystem
(planarian)
• Parasitic: tapeworm and flukes
AFTER THIS
PHYLUM ALL
ANIMALS HAVE
SYTEMS FOR
DIFFERENT
FUNCTIONS
4) Phylum Nematoda (round
worm)
• They have exoskeleton which is made of
cuticle. They have complete digestive
tract with two openings (mouth and anus)
• Some of them are important detritivores –
decomposers
• Some of them are parasites for humasn
and plants e.g. trichinella spiralis is a
parasite which is taken by uncooked pork
meat
5) Phylum Mollusca
• They have muscular foot, developed nervous
system and other systems and soft body. They
do not have skeleton. They have true coelom.
• There are three main groups of mollusca.
• Gastropoda: live in water and on land, they are
herbivores-e.g snail
• Bivalves: Aquatic animals. They have shell. They
are filter feeders – e.g: mussel, scallop
• Cephalopoda: Aquatic animals which have large
brain. Carnivores – e.g: octopus
AFTER THIS PHYLUM
SEGMETATION STARTS!!!
• Segmentation: subdivision of the body into parts. This
feature played a central role in the evolution of many
complex animals.
• Segmented worms have segmented body but not
segmented organs.
• Arthropods have more specialized segments. Head
thorax and abdomen
• Mammals have segments: head, chest cavity, abdomen
• *** Advantage of having segmented body is: it allows
flexibility and mobility. This is adaptation for movement.
Movement to catch prey or digest efficiently.
6) Phylum annelida
• They consist of body segments.
• They live in sea, fresh water and damp
soil.
• e.g. Earth worm, Polychaetes, Leechs
• Most of them are scavengers
• Body is externally protected by thin, elastic
protein cuticle
7) Phylum Athropoda
• They have systems and jointed legs, chitin
exoskeleton.
• Some of them are carnivores, some of
them are herbivores .
• They have open circulatory system
• They have distinct group of segments form
head, thorax, abdomen.
Some classes;
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a. crabs
b. Spiders (arachnids)
c. Crustaceans
d. Millipedes and
centipedes
• e. Insects
•milipede
8) Phylum Echinodermata
• All live in marine. They do not have body
segments.
• Most are radial symmetrical in adult,
bilateral in larvae.
• They have spiny skin, endoskeleton an
water vascular system.
• They are carnivores.
• e.g: sea urchin, seastar
9) Phylum Chordota
Main characteristics of chordate:
• Dorsal nerve cord
• Notochord : a flexible, supportive rod
between digestive tract nerve cord
• Pharyngeal slits (gill structure in the
pharynx)
• Muscular anal tail
a. Invertebrate chordota
• Invertebrate chordate do not have
segmented backbone.
• There are two main groups: Tunicate and
lancelets.
Both groups are suspension feeders
b. Vertebrate chordata
• Nerve cord is protected by bone
• Sharks  made of cartilage
 no proper bones on the nerve
cord (transition between vertebrate and
invertebrate)
Classes:
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fish
amphibian
reptiles
birds
mammals
Fish
• Respiration  by gills,
• Locomotion  by fins
• External fertilization  young organisms
are growing outside of mother’s body
Amphibians
• Partially terrestrial, partially aquatic (Adapt
water for reproduction)
• Moist skin (respiration by skin)
• External fertilization
• Adapt land for respiration, excretion and
movement
• Respiration is by gills for tadpoles and by
lungs, and skin for adult frogs
What are the differences between
amphibians and fish??
• Gills become lungs
• Fins become forelimbs
Reptiles
• Dry skin with scales
• Respiration by lungs -- inside the body
(why?)
• İnternal fertilization
PREPARED BY CANAN ÇERMEN
SOURCE: BIOLOGY: CONCEPTS AND CONNECTIONS BY CAMPBELL, REECE, MITCHELL, TAYLOR
Compare reptiles and
amphibians??
• Amphibians make external
fertilization,reptiles internal
• Reptiles have tough, scaly skin but
amphibians have thin, moist skin
• Reptiles have stronger skeleton than
amphibians, more efficient lungs and
better developed nervous system
Birds
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Skin is covered by feathers
Legs have scales
Strong and light skeleton with air spaces
High body temperature for internal
regulation(endothermic)
High metabolic rate
Internal fertilization
No teeth and jaws
They have horny beaks
Mammals
• They have hair (furs) which insulates and
protects the body
• They have mammary glands to provide milk for
the young
• Differentiated teeth and three middle ear bones
• İnternal fertilization
• Endothermic organisms
• Parental care for the young
• Muscular diaphragm helps respiration
There are 3 main groups...
• Egg laying mammals (female organisms
lay eggs. When the eggs hatch, female
takes the baby and gives milk)
• Pouched mammals
• Placental mammals
Egg laying mammals
• Female lays eggs
• When the young hatch, they lick milk
secreted by their mother’s mammary
glands
Pouched mammals
• Embryo begins development in the
mother’s uterus
• Young are born undeveloped
• Mother put the young into pouch & young
animals attaches its mouth to a mammary
gland nipple and gets milk.
• e.g: kangroo
Placental mammals
• Placenta forms both embryonic membrane
& maternal uterus wall
• In placenta blood vessels of mother come
closer  material exchange by diffusion
• Development is completed in placenta