Transcript Kingdom Animalia

Introduction to Animals
Essential Questions:
What makes an animal an animal?
How are animals classified?
Kingdom Animalia
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Eukaryotic
 Heterotrophic
 Multicellular
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Tissues and organs
formed by specialized cells
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No cell walls
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Likely evolved from
animal-like protists
Essential Functions
All animals carry out the following:
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Obtain food from the environment
Exchange O2 & CO2 through skin, gills, lungs, etc
Move materials around body
Get rid of wastes
Process information with nerves
All animals are motile at some point
Most reproduce sexually, some asexually
Reproduction & Development
 Animals
mainly reproduce sexually
Fertilization – sperm meets egg, either within
or outside the body
 External fertilization (in water)
 Internal fertilization (on land)
What are the positives
and negatives of each
type of fertilization?
Reproduction & Development
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Steps of Development:
Fertilization results in a
unicellular zygote
The unicellular zygote
divides by mitosis =
cleavage
A hollow ball of cells
(blastula) forms
Gastrulation (folding
inward) forms 2 cells layers:
ectoderm and endoderm
Mesoderm forms
Coelomate vs Acoelomates
Coelom – fluid filled cavity that supports internal
organs.
 Acoelomates – no internal cavity. Example: Flatworms
 Pseudocoelomates – body cavity develops between
endoderm and mesoderm. Example: Roundworms
 Coelomates – internal organs suspended in a body
cavity surrounded by mesoderm. Example: Earthworms
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Why the Coelom?
The coelom is significant
because as animals evolved, so
did the presence of a complex
body cavity to support more
complex organs!
Symmetry
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Animals can be described in terms of their symmetry:
Asymmetry – irregular in shape Example: Sponge
Radial Symmetry – can be divided through along any plane
into halves from the mouth. Example: Anemone
Bilateral Symmetry – can be divided lengthwise into 2 mirror
images. Example: Humans
 Cephalization: concentration of sense organs at the front
(top) of the body
Body Positioning
Bisymmetrical animals have 4 parts:
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Anterior: the head end,
where sensory organs are
located
 Posterior: the tail end
(anus)
 Dorsal: Back surface where
the spine is located
 Ventral: The belly side
Framework for support: Skeletons
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Exoskeletons – hard, waxy
covering on the exterior of the
body.
 Prevent water loss, protect soft
tissues
Endoskeletons – internal skeleton
for support made of Calcium
Carbonate, cartilage or bone
 Protects internal organs and an
internal brace for muscles to pull
against
To survive on land, why is it important to have a
strong skeleton?
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Framework for support: Skeletons
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Invertebrates – an
animal without a
backbone; usually has
exoskeleton
 Echinoderms have
endoskeletons
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Vertebrates – an animal
with a backbone;
bilaterally symmetry;
exoskeleton
Invertebrates
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Make up 95% of all animals
 No backbone, or vertebral column.
Most have exoskeletons.
 Open circulatory systems (with a one
chambered “heart”)
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Cannot process Oxygen very well, restricts their
size and survival on land.
Invertebrate Phyla
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Phylum Porifera - Sponges
Phylum Cnidaria – Corals, Hydra &
Jellyfish
Phylum Platyhelminthes - Flatworms
Phylum Nematoda – Roundworms
Phylum Mollusca – Snails, squid &
Clams
Phylum Annelida - Segmented Worms
Phylum Arthropoda – Insects, spiders,
lobsters
Phylum Enchinodermata – Starfish
Invertebrate members of Phylum
Chordata– Sea squirts, Lancelets
Phylum Annelida
 The
segmented
worms. Example:
earthworms, leeches
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Segmentation
allows movement
of individual parts
 Possess
a true
coelom
 Specialized organs
and systems
Phylum Chordata
Subphylum Vertebrata
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Class Agnatha (jawless fishes)
Class Chondrichthyes
(cartilaginous fishes)
Class Osteichthyes (bony fishes)
Class Amphibia (amphibians)
Class Reptilia (reptiles)
Class Aves (birds)
Class Mammalia (mammals)
Vertebrates
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5% of all animals
 Have a vertebral column.
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The backbone gives support to the
body and protection to the spinal
cord
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Have endoskeletons.
 Closed circulatory system with
a multichambered heart
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Classification: Kingdom – Animalia,
Phylum – Chordata, Subphylum Vertebrata
Types of Mammals
– based on type
of reproduction
 Subclasses
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Placental (95%) – young fully
develops in uterus before
birth
Marsupials – short period of
development inside the
mother followed by a second
period of development inside
pouch
Monotremes - lay eggs. #
species: platypus and 2
echidnas
Vertebrates: Am I hot or not?
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The major difference between
vertebrates is whether or not they can
regulate their own body temperature.
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Ectotherms – regulated by
environment
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Example: fish, frogs, snakes
Endotherms – regulated by their
own body
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Example: mammals
Animals that are ectothermic (like snakes)
don’t require food as much as endotherms.
• What does this indicate about the
relationship between food requirements
and the generation of body heat?
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• How does this fact restrict where
certain types of animals can live?
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• If the environment were to suddenly
get cold (like an ice age), which of the
animals could survive?
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