Transcript Classification

Animalia Kingdom
Animals are….
• Heterotrophs
• Eukaryotes
• Multicellular
organisms
• Have cells that lack
cell walls
Development of animal embryos
Most animal embryos are differentiated into three layers called germ
layers:
1.
Endoderm- innermost- develops into the lining of the digestive &
respiratory tract.
2.
Mesoderm-middle-develops into muscles, circulatory,
reproductive, and excretory systems.
3.
Ectoderm-outermost-develops into sense organs, nerves, outer
skin layer.
Terms to use with animals:
Symmetry- body plan of how parts are arranged.
Bilateral, radial, asymmetry
Cephalization- to have a head
Anterior- toward the head
Posterior- toward tail
Dorsal- the back
Ventral- the belly
Animal phyla
Porifera - Sponges
Filter feeders
Motile (can move)
Asymmetrical
Simplest animal
No tissues or organs
Cnidaria Phylum – Stinging Cells
• First animal to have
the 3 germ layers
• Radial symmetry
• Have stinging cellscnidocytes- shoots out
a barbed nematocyst
to spear prey
• Jellyfish, hydra
• Appeared on earth
after Porifera
Polyp stationary,
vase-shaped
Platyhelminthes
• The flatworms: tapeworm, fluke,
planaria
• Bilateral symmetry
• Evolutionary significance- simplest
animals to have developed organs and
cephalization
• Some free-living and some parasitic
• Acoelomate: No body cavity between
the digestive tract and skin
• Followed Cnidaria on appearance on
Earth
Nematoda
• Followed flat worms in
appearance on Earth
• Round worms- first animal to
develop a body cavity- helps
with organ function• Bilateral symmetry
• Some free living and some
parasites
• Ex.- hookworms, nemotodes
Mollusca
• Appeared after the flat
worms on Earth
• Developed a better body
cavity called a coelom.
• Body is not segmented
• Has a radula- rasping
tongue-like organ
• Ex. Snails and slugs
(Gastropods), squids
octopus (Cephalopods),
clams (Bivalves)
Annelida
• Appeared on Earth after
Mollusca
• First segmented animals
(very important to advanced
body structure)
• Coelom
• Have a pharynx, crop, and
intestine, brain, and
circulatory system
• Earthworms, leeches,
fireworm
Arthropoda
• Appeared on Earth after
segmented worms
• First animals to have jointed
appendanges
• Have coelom, segmented
body
• Have an exoskeleton made
of chitin
• Beetles, crab, scorpion,
dragonfly, insects
Echinodermata – Spiny skinned
• Evolved following
Arthropods
• First animals to develop
an endoskeleton or
internal skeleton
• Starfish, sea urchin
• Water vascular system
for movement
Chordata
Have these 3 characteristics at some time in
their life
1. Nerve cord- nerves attach here and go to
different body parts
2. Notochord- long stiff rod forming beneath
the nerve cord
3. Pharyngeal slits- form in pharynx –
connects mouth to digestive tract and
windpipe.
The Vertebrates
• Two evolutionary developments are the head and the vertebral
column.
• All vertebrates have an internal skeleton made of bone or cartilage.
The Classes of the Phylum
Chordata
Class: Agnatha
• Jawless fish- first
vertebrates
• Cartilage
• Lamprey- parasite
• Hagfish
• No scales
• Ectotherms
• 2 chambered heart
Class: Chondrichthyes
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Followed jawless fish
Have jaws
Paired fins
No scales
Cartilage
Streamlined bodies
Sharks and rays
Ectotherms
2 chambered heart
Osteoichthyes
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Bony fish
Paired fins
Scales
Swim bladder
Evolved from cartilage
fish
• Sharks and rays
• Ectotherms
• 2 chambered heart
Class Amphibia
• Half life: tadpoles live in water
and have gills and frogs live on
land and have lungs
• Developed from bony fish
• First vertebrates to live on land
• Frogs and salamanders
• Eggs not water tight so they have
to be laid in moist environment
• Ectotherms
• 3 chambered heart (2 atria, 1
ventricle)
Class Reptilia
• Scaly skin- keeps body
from drying out
• Can live on land
• Internal fertilization and
water tight eggs- amniotic
• Ectothermic (cold blooded)
• Evolved from amphibians
• Turtles, lizards, snakes
• 2 atria and ventricle
partially divided in the
heart
Class Aves
• The birds
• Endotherms
• Probably evolved from the
dinosaurs
• Feathers for insulation
• Archaeopteryx was the first
bird
• Wings
• Have gizzard, crop,
stomach, intestines
• 4 chambered heart
Class Mammalia
• Have mammary glands- provide
milk for young
• Evolved from therapsids (now
extinct warm blooded reptile)
• Have hair or fur
• Endotherm
• 4 chambered heart
• Divided into placental,
marsupials, and monotremes.
Koala
The types of mammals
• Placental- that’s usdevelop in a placenta
inside the mother.
• Marsupial- After birth
stays in a pouch on the
mother to complete
development- kangaroos
and opossums.
• Monotremes- Lay eggsduck billed platypus