Exam 3 Flashcards
Types of symmetry
Radial
Biradial
Bilateral
Radial Symmetry
- body can be divided like a pie and make equal slices
- can be divided in half many times and one side always looks like the other
- usually sessile, floating, or weak swimming
Biradial Symmetry
Certain few parts make it so only 2 planes of division result in similar halves (otherwise body is radial)
-usually sessile, floating, or weak swimming
Bilateral Symmetry
body can be divided in half to make 2 halves
- animals with more movement
- associated with cephalization
Cranial
Anterior or head region
Caudal
Posterior or tail end
Medial
relative, towards the midline of the body
ex: sternum, heart
Lateral
relative, towards the side of the body
Distal
relative, something farther from center of body
Proximal
relative, something closer to center of body
peritoneal lining
tissues connected to gut cacvity
What organisms have peritoneal lining and which don’t?
psuedocoelomates don’t
eucoelomates do
Schizocoelomates
coelom forms from splitting of mesoderm bands in development
annelids, arthropods, molluscs
Enterocoelomates
coelom forms from mesodermal pouches of early gut
echnidoderms, chordates
Sponge Anatomy
- body is series of canals and pores
- radial or asymmetric
- water movement is created by choanocytes
Choanocytes
Cells that create water movement
Have flagellum surrounded by collar
Maintain water flow and trap food particles
Ostia
smaller incurrent pores
Osculum
Larger outcurrent pores
Asconoid
one main chamber
Suconoid
Choanocytes in multiple side chambers
Leucanoid
lots of small chambers
Mesohyl
Gelatinous matrix the mass of cells are embedded in
Structural support or sponges
Spicules-calcium carbonate or silica (pointy)
Spongen- collagen protein (web-like)
What makes a sponge more flexible
fewer spicules and more spongen
Digestion of sponges
intracellular
Archaeocytes
amoebid cells that digest and transfer food
form other cells that make spicules and collagen
Gemmules
internal buds in sponge reproduction
held in parent’s body until death and good conditions
Asexual reproduction of sponges
fragmentation and budding (gemmules)
Sexual reproduction of sponges
most are monoecious and viviparous
live birth of ciliated larvae after development in parent
Some species are oviparous
Dispersal in sponges
larve parenchymula are free swimming and find a suitable spot before maturing
Germ layers in cnidarians
Epidermis and gastrodermis
Mesoglea
In cnidarians
Extracellular jelly mattix b/w the 2 germ layers
Oral/aboral
The ends of cnidarians
No head
Side with mouth and side without
- Nematocysts
2. Cnidocytes
- Stinging and adhesive organelles
2. Produce nematocysts
Digestion for cnidarians
Extracellular in gastrovascular cavity
Cnidarian nervous system
Nerve net with statocyst and ocelli (light sensitive organs)
Reproduction in cnidarians
Asexual-budding in polyps
Sexual-medusae and some polyps produce gametes (dioecious or monoecious)
-planula larvae
Siphonoglyph
wall of pharynx, ciliated, moves water in and out of animal
Anthozoa
Acontia
2nd round of nematocysts near mouth
Anthozoa
Corals
Anthozoa
morphologically similar to anemones but secrete a calcareous cup
Scyphozoa bell
has indentations with a pair of lappets (folds) that surround a rhopalium (bears statocysts and ocelli)
Anthozoa species
anemones, corals, sea fans, sea pens
Strobila
formed by polyp stage of scyphozoan
forms a juvenile medusa (ephyrae) asexually
Cubozoa species
box jelly, sea wasp
Velarium
edges of cubozoa turned inward to create a jet propulsion
Hydrozoa species
man of war, hydra
Velum
internal projection of bell margin
Hydrozoa
Collenchyme
Gelatinous material in between epidermis and gastrodermis of ctenaphora
Colloblasts
glue cells that secrete sticky substance
used for food capture for ctenaphora
Auricles
tactile and chemosensitive, orient towards food, mates, and away from predators
Platyhelminthes
Lophotrochozoa characteristics
Tophophore feeding structure
Trochophore larvae
