Transcript Animalia

Kingdom Animalia
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Eukaryotic
No cell wall
Multicellular
Heterotrophic
Most are capable of motion
About 30 phyla
Characteristics for animal classification
• Symmetry-the arrangement of body parts around
the main axis of the body
1. Bilateral-two almost identical halves
2.Radial symmetry around the axis
3. Asymmetrical-lack of symmetry
• Digestive systems: sac or tube where food breaks
down into small particles
1. Incomplete-one opening
2. Complete-two openings
3. Absent
Figure 23.3 Symmetry Is an Equivalence in Body Sections
Radial symmetry:
Symmetry around a central point
Asymmetry:
No planes of symmetry
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Bilateral symmetry:
Characteristics for animal
classification
• Body Segmentation-multiple repeating units
• Skeletal systems: provide support for the
body
1. Exoskeleton - a hard skeleton on the outside
of the body (calcium carbonate shells, chitin,
silica)
2. Endoskeleton - a hard skeleton inside the
body, usually composed of bone or cartilage
Characteristics for animal
classification
• Circulatory systems-distribute nutrients to all
parts of the body and removes waste
products. [Not found in Cnidaria,
Platyhelminthes, or Nematoda].
1.Closed-the blood is always inside of blood
vessels (all vertebrates, some molluscs).
2.Open-the blood fills the body cavity
(arthropods, some molluscs)
Classification system
• domain
• kingdom - a group of related phyla
• phylum (plural = phyla) - a group of related classes. It
is called a division in Botany.
• class - a group of related orders
• order - a group of related families
• family - a group of related genera
• genus (plural = genera) - a group of related species
• species - a kind of living organism . All organisms
who can potentially reproduce together under natural
conditions and produce fertile offspring.
Figure 23.2 A Family Tree for Animals
Porifera
(sponges)
Cnidaria
Platyhelminthes
Annelida
Mollusca
(flatworms)
Nematoda
Arthropoda
Echinodermata
Chordata
(roundworms)
Protostomes
tissues
symmetry
ancestral protist
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bilateral symmetry
Deuterostomes
Early embryo
Protostomes
anus
invagination
mouth
blastopore
Deuterostomes
mouth
invagination
anus
blastopore
All animals pass through a blastula stage of development, the blastula being a hollow
ball of cells. The blastula then invaginates to form a structure that develops into the
animal’s gut. The opening to this invagination is called a blastopore. In protostomes,
the blastopore becomes the mouth. In deuterostomes, by contrast, the blastopore
becomes the anus.
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Table 23.1 Animal Phyla
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Phylum Porifera ( pore-filled)
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Example: Sponges
Asymmetry or radial symmetry
Endoskeleton
Filter feeders (body with pores)
They are attached (cannot move)
marine
Figure 23.6 Sponges: A Body Plan for a Simple Lifestyle
Inner cells with
flagella create
currents.
The currents
cause water to
flow into pores
and out at top.
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Figure 23.7 Sponge Diversity
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Phylum Cnidaria
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EX: coral, hydra, jellyfish, sea anemone
radial symmetry
incomplete digestive system (one opening)
no segmentation
no circulatory system
a circle of tentacles surrounds the mouth
have a cell structure called a nematocyst for
stinging prey
Figure 23.8a Jellyfish
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Figure 23.8b Sea anemone
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Figure 23.8c Coral polyps
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Figure 23.9 Two Stages of Life for Many Cnidarians
medusa
gastric
cavity
tentacles mouth
mouth
gastric
cavity
polyp
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tentacles
PHYLUM PLATYHELMINTHES
= flatworms
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EX: planaria, flukes, tapeworms
bilateral symmetry
incomplete digestive system (one opening)
no segmentation
no circulatory system
concentration of sensory organs at anterior
“head” end
Figure 23.12a Flatworm anatomy
Flatworm anatomy
primitive eyes
nerve cords
genital
pore
cerebral
ganglia
penis
testes
ovaries
Nervous system includes primitive eyes and two
collections of nerve cells, the cerebral ganglia, that connect to
nerve cords that run the length of the animal. In reproduction,
Dugesia is hermaphroditic, meaning it possesses male sex
organs (testes and penis) as well as female sex organs (ovaries
and other structures). When two Dugesia copulate, each
projects its penis and inserts it in the genital pore of the other.
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Figure 23.11 Flatworms
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PHYLUM NEMATODA
= round worms
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Examples: Ascaris, Toxocara canis
bilateral symmetry
complete digestive system
no segmentation
no circulatory system
body is round in cross section
free living organisms or parasitic organisms
PHYLUM ANNELIDA
= segmented worms
• EX: earthworm, clam worm, blood worm,
leech
• bilateral symmetry
• complete digestive system
• segmentation - the body is composed of many
nearly identical segments
• closed circulatory system
Figure 23.13 The Body Plan of an Earthworm
dorsal
blood vessel
intestine
brain
mouth
“hearts”
coelomic space
muscular walls
between
segments
anus
pairs of bristles
segments
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Figure 23.14a Hawaiian Christmas tree worm
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Figure 23.14b Medicinal leech
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PHYLUM MOLLUSCA - the mollusks
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bilateral symmetry
complete digestive system
no segmentation in adults
open circulatory system
PHYLUM MOLLUSCA - the mollusks
• EX: snails, slugs, clams, scallops, oysters,
octopus, squid
• soft body. Some have a muscular foot used
for movement
• a protective shell made of calcium carbonate
sometimes covers the soft body. The shell
does support the body somewhat, but is not a
skeletal system
Snail (Gastropod)
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Squid (Cephalopod)
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Scallop (Bivalve)
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PHYLUM ARTHROPODA arthropods
• EX: insects, spiders, ticks, scorpions,
centipedes, millipedes, crustaceans (lobsters,
crabs, etc.),
• the largest animal phylum
• bilateral symmetry
• complete digestive system
• open circulatory system
• exoskeleton
PHYLUM ARTHROPODA arthropods
• Segmentation – but many segments are fused
into larger body regions (e.g., some of the 20
segments of an insect have fused together to
form 3 body regions: head, thorax, and
abdomen)
• many pairs of jointed appendages - arthropod
means “jointed leg”
Class Insects
• Example: Beetles, flies, bees,
grasshoppers
• largest group
• 6 legs, 2 pair wings, 1 pair antennae
Insect Features
head
thorax
abdomen
exoskeleton
muscles
joint
segments
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Class Crustaceans
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Example: Crabs, lobsters , shrimp, barnacles
2 part body
gills
many appendages
Crustacean Diversity
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Crustacean Diversity
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Crustacean Diversity
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Class Centipedes and Millipedes
MANY BODY SEGMENTS AND APPENDAGE
Class Horseshoe crabs (most closely related to arachnids = spiders)
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Class Arachnids
• Example: Spider, tick, scorpion
• 8 legs, no wings, no antennae
• Fang-like mouth parts
Class Arachnid Diversity
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PHYLUM ECHINODERMATA
“spiny-skinned” animals
• EX: starfish, sea urchin, sea cucumber, sea lily,
sand dollar
• radial symmetry in adults (the body is usually
subdivided into five parts)
• complete digestive system
• open circulatory system
• no segmentation
PHYLUM ECHINODERMATA
“spiny-skinned” animals
• endoskeleton made of calcified plates
• tube feet use suction, to move and feed
• rough skin has spines
Figure 23.24a Sea star
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Feather star. Related to sea lily.
Has 10 arms, each of which branches many times.
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PHYLUM CHORDATA - chordates
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EX: fish, birds, snakes, humans
bilateral symmetry
complete digestive system
modified segmentation - segmentation is
easily seen in the embryo but becomes
somewhat hidden in the adult
• endoskeleton
• closed circulatory system
PHYLUM CHORDATA - the chordates
Chordates have three unique characteristics:
• notochord = hard supporting rod of the
skeleton along the back
• nerve cord running with the notochord
• pharyngeal gill slits - openings from inside the
pharynx to the environment. In fish, they
contain gills which are respiratory organs.
Three Universal Chordate Features
notochord
dorsal nerve cord
pharyngeal slits
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The Vertebrate Classes:
• The Chordates are subdivided into three
subphyla, but almost all species of chordate
are within the Subphylum Vertebrata, the
vertebrates.
• In the Vertebrata, the notochord is replaced
during development by a new rod made of
many pieces which is called the vertebral
column or backbone.
Subphylum Tunicates, a primitive chordate
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3 CLASSES OF FISH
1. Jawless fish (e.g., lamprey) - 50 species
2. Cartilaginous fish = fish with a skeleton of
cartilage (sharks, rays) - 800 species
3. Bony fish = fish with a skeleton of bone 18,000 species
Lamprey. No Jaw, a Predator
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Cartilaginous Fish. A ray
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CLASS AMPHIBIA - amphibians
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EX: salamanders, frogs, toads
aquatic larvae with gills
adults with lungs
three chambered heart
Moist skin
no teeth, claws, or scales
Figure 23.33 Amphibian Life Cycle
female
male
egg
mature
frog
fertilized
egg
sperm
immature
frog
tadpole
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developing embryo
CLASS REPTILIA - reptiles
• EX: lizards, snakes, crocodiles, turtles
• three chambered heart
• dry skin covered with scales. (The shell of a
turtle is made of scales. The inner scales
become bony and attach to the
endoskeleton.)
• usually possess claws and teeth
CLASS AVES - birds
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Example: finch, blue bird
four chambered heart
warm blooded
skin covered with feathers
forelimbs adapted as wings
hollow bones - reduces the bird’s weight so
that flying is easier
CLASS MAMMALIA - mammals
• EX: kangaroo, mouse, bat, dog, cow, humans,
fox, cat.
• four chambered heart
• warm blooded
• skin covered with hair
• modified sweat glands called mammary
glands to produce milk
Mammal Diversity Plecental mammal, Bear
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Mammal Diversity Marsupial Kangaroo
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Mammal Diversity monotreme Duck-billed platypus
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