Transcript Simple Animals - Veritas Science

Sponges, Cnidarians, Worms, etc….
The Animal Kingdom
 Multicellular, Eukaryotic, Sexual Reproduction,
Movement.
 Symmetry: A) asymmetry
B) radial
C) bilateral
Lifestyle: A) sessile – “filter feeder”
B) parasitic – benefits (feeds) off of another
individual
C) Predator/Prey Relationship – hunt or be
hunted
- carnivore
- herbivore
- scavenger
- omnivore
Animal Kingdom (cont)
 Organization: - cells-tissues-organs-organ systems
ORGANISM
Body plan – hydrostatic skeleton = uses water pressure
to form shapes
-Cephalization = Sensory organs are
centralized towards a head
= Easier to protect, If you
lead w/the head you find
danger/prey/etc faster
Body Plan (cont)
 Chordates = Does it have a dorsal hollow nerve cord?
Vertebrates vs Invertebrates: Does it have a backbone?
 Protostomes: Only one opening to the digestive system
 Deuterostomes: Has both a mouth and an anus
“tube-in-tube design”
Body Plan (cont)
-Segmentation = repeating body sections
= requires less DNA
- Exoskeleton = skeleton on the outside
---VS--- Endoskeleton = skeleton on the inside
Anatomical Directions
 Anterior = towards front; Posterior = towards back
 Superior = above; Inferior = below
 Proximal = towards body/trunk; Distal = away from
body/trunk
 Medullay= towards center; Cortical= towards surface
 Medial=towards midline; Lateral=away from midline
 Cephalic = towards head; Caudal = towards tail
antaennalope
Phylum = Porifera
- The Sponges; -por-: hole
Real Sponge
Synthetic Sponge
- Sessile = Filter-Feeders – the sift through the water for
food
- Mostly asymmetrical; Some radial symmetry displayed
- Organized to the tissue level
- Displays movement with sperm cells and choanocytes
Sponge Parts and What they Do




Osculum-Large opening where filtered water exits
Central Cavity-Space n the middle of the sponge
Porocytes-Open and close pores to allow water flow
Choanocytes-Flagella provide current to draw water
in for feeding
 Amoebocytes-Absorb and
digest food
particles
 Pinacocytes-Tough cells
on outside
layer.
 Spicules-Spines made by
sponge to provide
structure (skeleton)

Sponge Life-Cycle
- Asexual Reproduction through
Asexual budding:
A piece breaks off and form a new sponge
 Sexual reproduction: 1) Sperm in released into waters
2)Sperm finds another sponge to
fertilize
3)Fertilized eggs form gemmules
that catch the current and land
elsewhere to grow
4)Gemmules resemble the polyp
form of a Cnidarian
5) All sponges are male and
female
Porifera Diagram
 Complete a diagram of a sponge in cross-section. If you
require an inset that is magnified for clarity, please use one.
Make sure to include the following structures: -osculum
-central cavity
-pores/pore cells
-choanocyte
-spicule
-Epidermal cell
-Amoebocyte
****arrows indicating the flow of water****
**Write down the function of each structure on the back**
Phylum = Cnidaria
Cnidarians
 -cnido-: sting; All cnidarians have cnidocytes=stinging
cells
 Both forms of cnidarians use tentacles with
cnidocytes to inject venom then get prey into their
mouths
HYDRA:
http://www.youtube.com/watch?v=yqXkaZwiu6s&feature=related
HYDRA GRABBING DAPHNIA:
http://www.youtube.com/watch?v=G188PDx73i8
HYDRA FEEDING:
http://www.blinkx.com/watch-video/hydrafeeding/w2UQnb8IS9qrDg6Dr2yGwA
 Body Plan: Either Polyp: 
Ex: coral, anemone
or Medusa:

Ex: jellyfish
 Life-cycle = polyp state
usually uses a
medusa phase
to be mobile
during sexual
reproduction.
2 different Body Types
 Polyp: Coral, Anemone, Hydra
 Medusa: Jellyfish
Cnidarians All Have Cnidocytes
 Cnidocytes = stinging cells
 Usually located in some type of tentacle in order to
find prey.
 The cnidocyte launches a venomous harpoon (the
nematocyst) in to the prey.
 The venom has varying toxicity.
Animal Characteristics of
Cnidarians
 Hydrostatic Skeleton
 Moves to hunt for its food, and for reproductive
purposes in the medusa form.
 Has organized to the organ level: tentacles,
gastrovascular cavity.
 Gastrovascular Cavity: Large central cavity with one
opening (mouth/stoma) where digestion occurs.
Roundworms, Flatworms and Segmented Worms
Roundworms = Nematodes
 Unsegmented worms with body cavities and tough
outer cuticle for protection
 Digestive system has 2 openings: Mouth  Anus
“Tube-in-Tube Design”
- saves time in efficiency
- allows more time for digestion
- prevents disease
 Simplest animals to have bilateral symmetry and
cephalization
 Some are free-living (non-parasitic)
- Ascaris lumbracoides feeds on vegetation
 Many are parasitic = they live off of another’s acquired
resources.
- complex life-cycles
- Hookworm = bore into host’s foot from the
ground.
Makes you crave dirt
- Trichinosis = Uncooked pork
- Heartworm = transferred to dogs from
mosquitoes
- Pinworm = #1 parasite in the US
get from unwashed hands
lives in the intestines
- Elephantiasis = parasite clogs drainage tubes
Hookworm
Complicated Parasite Life-Style
Trichinosis/ Elephantiasis
Others
Flatworms = Platyhelminthes
 Free-living varieties
- Planaria- live in lakes and pools of water
- Protostomes – Pharynx
- eyespots – detect light
- Flame cells – excretion (like
kidneys)
 Parasitic- Flukes- internal parasites
- attaches with suckers
- Has same cuticle as some nematodes
- Simple digestive system since they
just use the host’s
 Tapeworms- Long Ribbon-like internal
parasites
- Many repeating segments
called proglottids each
containing a set of eggs
- Has a head called a scolex that grabs
onto the inside of digestive tract.
- No Mouth = ?Why?
Segmented Worms = Annelids
 3 Classes: 1) Polycheates = Tubeworms
2) Hirudinea = Leeches 
blood-sucking
parasites
3) Oligocheates = Earthworms
Annelids Developed Organ Systems
to Complete Functions
 Excretory system- Nephridia = remove wastes
 Reproductive- Clittellum = where sex occurs
- Ovaries and Testes = hermaphroditic
(why?)
Digestive – Mouth  Pharynx  Esophagous  Crop
 Gizzard  Intestines  Anus
- Crop = food storage
- Gizzard = muscular structure used to grind
food without use of teeth
 Locomotion – Circular Muscles
- Longitudinal muscles
- Setae
 Circulatory – Blood vessels
- Aortic arches
Nervous System – Ventral nerve cord
- Brain?
Earthworm Dissection
Be Able to Identify the Following:
 Crop
 Gizzard
 Mouth
 Anus
 Seminal Vessicles
 Aortic arches / Circulatory system
 Clitellum
 Setae
 A Segment