Transcript Symmetry

Kingdom Animalia
CHAPTERS 26-34
General Characteristics
 Kingdom Characteristics
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 All move at some point in their lifecycles
In our study of animals we will go from
SIMPLEST to most COMPLEX.
This evolutionary progression can be
observed through the following trends:
 Cells TissuesOrgans Systems
 Radial Symmetry  Bilateral Symmetry
 Aquatic  Terrestrial
 No cephalization  Cephalization
Symmetry
 Radial Symmetry - organism
can be cut in half in many
ways and the halves will be
mirror images.
 Bilateral Symmetry -
organism can be cut in half
one way to get two equal
halves.
Cephalization
 Cephalization- organism has a true anterior
end/head with concentration of nerve cells
This sea star is not
cephalized
This grasshopper
is cephalized
Phylum Porifera - sponges
Characteristics:
• means “pore bearer”
• simplest animals
• All aquatic
Feeding:
• filter feeding using protist-like choanocytes
Choanocyte
Nervous Response:
• Can produce toxins
Locomotion:
• Sessile (non-moving) adults with free-swimming
gametes (egg and sperm)
Skeletal System:
• Can be hard with spicules or soft with spongin
Reproduction:
• Reproduce both asexually (budding) and sexually
(gametes meet in open waters)
Symmetry:
Asymmetrical – no ends or sides
Phylum Cnidaria
Jellyfish, corals, sea anemone, hydra
Characteristics:
•First to have tissues
•Live in aquatic habitats
Feeding Mechanisms:
• Single body opening through which food
enters and waste leaves
• Digests food within gastrovascular cavity and
absorbs into tissues
Nervous response:
• Can detect light, gravity, and touch
• Stinging cells called
nematocysts found inside
cnidocytes are used for
defense and feeding
Locomotion:
• Polyps are sessile
• Medusas use jet propulsion
Skeletal System
• Two types of body
plan, polyp (sessile)
and medusa
Reproduction
• Sexual and asexual (budding) reproduction
Symmetry:
• Radial symmetry
Phylum Platyhelminthes
Flatworms: flukes,
turbellarians, tapeworms
Characteristics
• First group with organs
• First cephalized group
Feeding:
• Carnivores
• Scavengers
• Parasitic
Defense Mechanisms:
• Ganglia – cluster of nerve cells
• Eyespot – detects light
Locomotion:
• Cilia and muscles
Skeletal System (body plan):
Acoelomate - solid body construction
• There is no fluid-filled cavity (coelom)
Reproduction:
• Hermaphroditic - both sexes in one worm, two
worms line up and exchange sperm
Symmetry:
• Bilateral
Phylum Nematoda
Roundworms: hookworms, heartworms, and
pinworms
Characteristics:
• Freeliving and parasitic
Feeding Mechanisms:
• First group to have a separate mouth and anus
• “tube within a tube”
• Parasitic, predators, or herbivores
Defense Mechanisms:
• Ganglia (concentration of nervous tissue)
• Sense organs to detect
chemicals given off by
prey or hosts
Locomotion:
• Use muscles to move
through water or soil
Skeletal System (body plan)
• Pseudocoelomate - false body cavity
• There is a cavity, but it is not lined with
mesoderm tissue
Reproduction:
• Sexually, separate sexes
• Parasitic roundworms usually have more than
one host
Symmetry:
• bilateral
Phylum Annelida
Segmented worms: earthworms, leeches, polychaetes
Distinguishing Characteristics:
• Segments allow for more complex movement
• First group with true organs and systems
Symmetry:
• Bilateral
Skeletal System (Body Plan):
• Coelomate - true body cavity completely lined with
mesoderm
Reproduction:
• Hermaphroditic or separate sexes
• Clitellum (labeled below) is used for fertilization
Locomotion:
• Two types of muscles that work together for movement
• Setae on segments (hair-like bristles)
Feeding:
• Can be filter-feeders, predators, or detritovores (feed
on decaying materials)
Defense/ Nervous Response:
• Well-developed nervous system
• eyes
Phylum Mollusca
Class Gastropoda (snails & slugs),
Class Bivalvia (clams & scallops),
Class Cephalopoda (squids & octopi)
Characteristics:
• “soft bodied”
Symmetry:
• Bilateral
Skeletal System:
• Foot – flat part of snails or tentacles of cephalopods
• Shell – internal or external
• Mantle – tissue
Reproduction:
• Sexually – most release gametes in open water
Feeding:
• Gastropods use a radula –
tongue-like with teeth
• Octopi use jaws
• Bivalves are filter-feeders
Defense:
• Hard shells secreted by the mantle
• Cephalopods are highly intelligent with eyes and tentacle
Locomotion:
• Gastropods secrete mucus
• Cephalopods use jet propulsion
Name that Structure!
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Copy down the description and write the name of the structure.
Uses flagella to move water through the sponge
A large hole at the top of the sponge
A spike-shaped structure inside sponges
A stinging structure within a cnidocyte that looks like a tiny hair
Cnidarian body form that is NOT sessile
Light-sensing structure seen in the Planaria
A cluster of nerve cells in the flatworm and roundworm
The posterior opening of the digestive tract, first seen in Nematodes
Structure used for fertilization in Annelids
Tissue in the Mollusks that secretes the shell
Phylum Arthropoda
Class Insecta
• 6 legs
• ex-Beetles, wasps, ants
Class Arachnida
• 8 legs
• Spiders, scorpions, ticks, mites
Class Crustacea
• 10 legs/appendages
• crabs, crayfish, barnacle
Characteristics:
• “jointed legged/footed”
• largest phylum-96% of all inverts
-73% of these are insects
• aquatic and terrestrial
Symmetry:
• bilateral
Nervous Response
• Well developed nervous system and brain
•Compound eyes that detect movement and color
Body Plan:
•Three body parts-head, thorax, and abdomen
• exoskeleton made of chitin-molted/shed as
they grow
Feeding
• A little bit of everything: Herbivores, carnivores,
omnivores, detritovores, filter-feeders,
parasites, and blood-suckers
Phylum
Echinodermata
• sea stars, sanddollars, sea biscuits, sea
urchins, and sea cucumbers
Characteristics
• spiny skinned animals
• only phylum that is entirely marine
• Often keystone species-removal of them from
their environment will cause the ecosystem to
crash
Symmetry- 5-part radial symmetry (bilateral as
larva)
Reproduction – sexual, release gametes in
open water
Locomotion
• watervascular system pumps water through
body for feeding and movement
• Tube feet
Feeding
• Sea stars open mollusks with tube feet, push
the stomach out of the mouth, and digest the
mollusk in its shell
Nervous Response
• no highly developed nervous system
• Sense light, gravity, and chemicals