2. Characteristics of Animals
HeterotrophyHeterotrophy
– Animals cannot produce their own foodAnimals cannot produce their own food
MobilityMobility
– They move: swim, crawl, walk, run,They move: swim, crawl, walk, run,
even flyeven fly
MulticellularityMulticellularity
– Some are microscopic…but they allSome are microscopic…but they all
have more than one cellhave more than one cell
DiploidyDiploidy
– They have two sets ofThey have two sets of
– chromosomes (there are a fewchromosomes (there are a few
exceptions)exceptions)
3. More Characteristics of
Animals
Sexual ReproductionSexual Reproduction
– Although some can reproduce asexually…mostAlthough some can reproduce asexually…most
reproduce sexuallyreproduce sexually
Absence of a Cell WallAbsence of a Cell Wall
– The only multicellular organism with no cell wallThe only multicellular organism with no cell wall
Blastula FormationBlastula Formation
– Form a hollow ball of cells called a blastula duringForm a hollow ball of cells called a blastula during
embryotic developmentembryotic development
TissuesTissues
– All animals except sponges have cells that areAll animals except sponges have cells that are
organized into tissuesorganized into tissues
4. Body Symmetry
Radial SymmetryRadial Symmetry
– Arranged around a central axisArranged around a central axis
Bilateral SymmetryBilateral Symmetry
– Mirror imagesMirror images
5. Advances in Animal
Body Design
Coelom - an internal bodyCoelom - an internal body
cavitycavity
– A place to put “stuff” like theA place to put “stuff” like the
internal organsinternal organs
SegmentationSegmentation
– Repeating similar unitsRepeating similar units
• Segments of an earthwormSegments of an earthworm
• A “six pack” abdomenA “six pack” abdomen
6. Invertebrates vs. Vertebrates
Invertebrates lack a spine orInvertebrates lack a spine or
backbonebackbone
– Examples: sponges, worms, insects,Examples: sponges, worms, insects,
starfish, and crabsstarfish, and crabs
Vertebrates have a spine orVertebrates have a spine or
backbone that protect a spinal cordbackbone that protect a spinal cord
– Examples: fish, amphibians, reptiles,Examples: fish, amphibians, reptiles,
birds and mammalsbirds and mammals
8. Sponges
Phylum Porifera
The simplest animalsThe simplest animals
Contains a “skeleton” of spicules madeContains a “skeleton” of spicules made
of silica or calcium carbonateof silica or calcium carbonate
Can reproduce asexually or sexuallyCan reproduce asexually or sexually
Beware of your wandering eye,
you little poriferan.
-Gary, SpongeBob Squarepants
10. Cnidarians
Have two formsHave two forms
– Medusa (mobile) and a polyp (attached)Medusa (mobile) and a polyp (attached)
Form tissuesForm tissues
Examples:Examples:
– Hydrozoans (hydra)Hydrozoans (hydra)
– Scyphozoans (jellyfish and boxjellies)Scyphozoans (jellyfish and boxjellies)
– Anthozoans (sea anemones and corals)Anthozoans (sea anemones and corals)
polyp
medusa
13. Platyhelminthes and Nematodes
OR Flatworms and Roundworms
Advance: bilateral symmetry allows forAdvance: bilateral symmetry allows for
cephalization (has a “head”)cephalization (has a “head”)
Flatworms can be parasitic or free-livingFlatworms can be parasitic or free-living
– Many free-living are marine…a few freshwaterMany free-living are marine…a few freshwater
– Parasitic include tapeworms and trematoadsParasitic include tapeworms and trematoads
Roundworms have a pseudocoelom (a partialRoundworms have a pseudocoelom (a partial
body cavity)body cavity)
– Parasitize plants and animalsParasitize plants and animals
– Common “worm” infection in dogs (and humansCommon “worm” infection in dogs (and humans
too!)too!)
15. Mollusks and Annelids
Snails, Squid, Clams, MarineSnails, Squid, Clams, Marine
worms and Earthwormsworms and Earthworms
16. Mollusks
Have a true coelomHave a true coelom
Most exhibit bilateral symmetryMost exhibit bilateral symmetry
Have organ systemsHave organ systems
Many have a shellMany have a shell
Types (Classes):Types (Classes):
– GastropodsGastropods
– BivalvesBivalves
– CephalopodsCephalopods
17. Gastropods (stomach foot)
Snails and slugsSnails and slugs
– Marine, freshwater, and terrestrialMarine, freshwater, and terrestrial
18. Bivalves (Two shells)
Oysters, clams, scallops and musclesOysters, clams, scallops and muscles
Have two shells held closed with twoHave two shells held closed with two
thick muscles (adductor muscles)thick muscles (adductor muscles)
20. Cephalopods
(Head foot)
Most of their body is a largeMost of their body is a large
“head” attached to tentacles“head” attached to tentacles
The most intelligent of allThe most intelligent of all
invertebrates (they have ainvertebrates (they have a
“brain”)“brain”)
Examples: squid, octopus,Examples: squid, octopus,
cuttlefish, and nautiluscuttlefish, and nautilus
21.
22.
23.
24.
25. Annelids
The first segmented animalsThe first segmented animals
Have a true coelomHave a true coelom
Primitive brainPrimitive brain
Examples: Marine worms, earthworms,Examples: Marine worms, earthworms,
and leechesand leeches
31. Features of Arthropods
CoelomCoelom
Jointed appendages (arms and legs)Jointed appendages (arms and legs)
Segmented bodySegmented body
Exoskeleton (hard outer skeleton)Exoskeleton (hard outer skeleton)
– Molting (shed their skeleton as they growMolting (shed their skeleton as they grow
larger)larger)
Examples of arthropods: insects, spiders,Examples of arthropods: insects, spiders,
scorpions, crustaceans (shrimp, lobsters,scorpions, crustaceans (shrimp, lobsters,
some zooplankton {yes, like plankton onsome zooplankton {yes, like plankton on
Sponge Bob})Sponge Bob})
35. Echinoderms and Invertebrate
Chordates
Echinoderms have a true coelom.Echinoderms have a true coelom.
Invertebrate chordates have a coelomInvertebrate chordates have a coelom
AND a nerve chord (precursor to aAND a nerve chord (precursor to a
spinal chord)…they have an internalspinal chord)…they have an internal
“skeleton” to protect their “central“skeleton” to protect their “central
nervous system”.nervous system”.
36. Echinoderms
Have a true coelomHave a true coelom
Have: an endoskeleton (internalHave: an endoskeleton (internal
skeleton), five-part radial symmetry,skeleton), five-part radial symmetry,
and a water vascular systemand a water vascular system
Examples: sea stars, sun stars, featherExamples: sea stars, sun stars, feather
stars, brittle stars, sea urchins, sandstars, brittle stars, sea urchins, sand
dollars, and sea cucumbersdollars, and sea cucumbers
37.
38.
39. Invertebrate Chordates
True coelomTrue coelom
Nerve chord protected by a stiff internalNerve chord protected by a stiff internal
rod called a notochordrod called a notochord
Examples: Tunicates and lanceletsExamples: Tunicates and lancelets
42. Importance of
Vertebrae
Vertebrae…Vertebrae…
– provide supportprovide support
– protect the dorsal nerve (or spinal cord)protect the dorsal nerve (or spinal cord)
– provide a site for muscle attachmentprovide a site for muscle attachment
Vertebrates also have a protective skullVertebrates also have a protective skull
that incases and protects the brainthat incases and protects the brain
Example: fish, amphibians, reptiles,Example: fish, amphibians, reptiles,
birds, and mammalsbirds, and mammals
43. Fish
Fish all have gills that they use toFish all have gills that they use to
breathe underwaterbreathe underwater
They use fins to move/swimThey use fins to move/swim
They have a single loopingThey have a single looping
circulatory system with 2circulatory system with 2
chambered heartchambered heart
They are cold-bloodedThey are cold-blooded
(ectothermic)(ectothermic)
44. Types of Fish
Jawless fishJawless fish
– Hagfish and lampreysHagfish and lampreys
Cartilaginous fishCartilaginous fish
– Sharks, rays, and skatesSharks, rays, and skates
Bony fishBony fish
– Gar, perch, sunfish, bass, minnows, angelGar, perch, sunfish, bass, minnows, angel
fish, etc.fish, etc.
51. Amphibians
Spend at least part of their life in the waterSpend at least part of their life in the water
(lay their eggs in water)(lay their eggs in water)
They have legs, lungs (most), and a 3They have legs, lungs (most), and a 3
chambered heart with a double loopingchambered heart with a double looping
circulatory systemcirculatory system
They are cold-blooded (ectothermic)They are cold-blooded (ectothermic)
Many undergo metamorphosis (tadpoles toMany undergo metamorphosis (tadpoles to
frogs for example)frogs for example)
Examples: frogs, toads, salamanders, andExamples: frogs, toads, salamanders, and
newtsnewts
52.
53.
54.
55.
56.
57.
58. Reptiles and Birds
Dinosaurs, lizards, snakes,Dinosaurs, lizards, snakes,
turtles, ducks, penguins, andturtles, ducks, penguins, and
more!!!more!!!
59. Dinosaurs
Dinosaurs were reptiles!Dinosaurs were reptiles!
– BUT some may have been warm blooded!BUT some may have been warm blooded!
Early birds were most likely very muchEarly birds were most likely very much
like reptiles with feathers!like reptiles with feathers!
– Archaeopterx is the earliest bird fossil everArchaeopterx is the earliest bird fossil ever
found…it had a long reptilian tail and nofound…it had a long reptilian tail and no
keeled sternum to anchor its flight muscleskeeled sternum to anchor its flight muscles
(so it didn’t fly)(so it didn’t fly)
61. Modern Reptiles
Cold-blooded (ectothermic)Cold-blooded (ectothermic)
Water tight skin and eggs adapted to landWater tight skin and eggs adapted to land
Some have a 4 chambered heart or a 3Some have a 4 chambered heart or a 3
chambered heart with a partial division of thechambered heart with a partial division of the
ventricle…and a double looping circulatoryventricle…and a double looping circulatory
systemsystem
They have lungsThey have lungs
Examples: lizards, snakes, turtles, tortoises,Examples: lizards, snakes, turtles, tortoises,
crocodiles, alligators, and tuatarascrocodiles, alligators, and tuataras
68. Tuataras
The tuatara is very ancient – it
is the only survivor of a large
group of reptiles that roamed
the earth at the same time as
dinosaurs (even before most
large dinosaurs). It hasn't
changed its form much in over
225 million years!
84. Other Placental Mammals
There are seven more orders includingThere are seven more orders including
various anteaters and “shrews”various anteaters and “shrews”
Edentata
Macroscelidea
(Elephant Shrew)
87. So what have we learned?
Animals are diverse!Animals are diverse!
They range from microscopicThey range from microscopic
rotifers to gigantic blue whales!!!rotifers to gigantic blue whales!!!
But they are all multicellular…But they are all multicellular…
They all have to eat somethingThey all have to eat something
(plants, animals, or both)(plants, animals, or both)
They can have bilateral or radialThey can have bilateral or radial
symmetry.symmetry.
They can be warm or coldThey can be warm or cold
blooded or have no blood at all!!!blooded or have no blood at all!!!
ANIMALS ARE COOL!!!ANIMALS ARE COOL!!!
