ch9.1- diversity of life Flashcards
porifera body symmetry
asymetrical
porifera tissue organization
no true tissue
porifera circulatory system
none
diffusion
porifera nervous system
none
porifera respiratory system
none
diffusion
porifera digestive system
intracellular digestion via amoebocytes
porifera general characteristeristics
Sessile (non-motile),
suspension feeders, aquatic habitats, earliest
animals, reproduce asexually (budding) or sexually
(hermaphrodites - has male and female sex
organs).
cnidaria examples
hydra, jellyfish, sea anemone, coral.
cnidaria body symmetry
Radial (around central axis).
cnidaria tissue organization
Diploblasts (two cellular
layers: endo- and ectoderm).
cnidaria circulatory system
none (diffusion)
cnidaria nervous system
Nerve net (neurons spread
apart), no brain.
cnidaria respiratory system
none- diffusion
cnidaria digestive system
Gastrovascular cavity (one
opening, two way digestion, acts as hydrostatic
skeleton to aid movement).
cnidaria general characteristics
Aquatic habitats, some
have cnidocytes (cells shooting poisonous barbs),
some have life cycles with a polyp stage
(non-motile, majority reproduce asexually but
some sexually).
platyhelminthes examples
E.g., flatworms, trematoda, flukes, tapeworm,
planaria.
platyhelminthes body symmetry
Bilateral (right and left halves,
axis at sagittal plane) with cephalization
(concentration of nervous and sensory organs in
the head; associated with bilateral symmetry).
platyhelminthes tissue organization
Triploblasts (three germ
layers).
platyhelminthes circulatory system
none- diffusion
platyhelminthes nervous system
Two nerve cords (dense nerve
bundle running along length of invertebrates),
anterior centralized ganglia (brain), some
planarians have eyespots.
platyhelminthes respiratory system
none- diffusion
platyhelminthes digestive ssytem
Gastrovascular cavity (except
tapeworms - absorb food).
platyhelminthes embryonic development
Protostome
(blastopore forms mouth).
platyhelminthes general characteristics
characteristics: Reproduce sexually
(hermaphrodites) or asexually (regeneration),
mainly aquatic habitats, parasitic lifestyles, most
primitive of triploblasts, has organs.
nematoda examples
roundworm, hookworm, trichinella, C.
elegans, ascaris.
nematoda body symmetry
bilateral
nematoda tissue organization
triploblasts
nematoda circulatory system
none- diffusion
nematoda nervous system
nerve chord and ring that surrounds esophagus
nematoda respiratory system
none- diffusion
nematoda digestive system
Alimentary canal (passage
between mouth and anus).
nematoda embryonic develpoment
protostome
nematoda general characteristics
Some have cuticle
(prevents degradation by host digestive system),
longitudinal muscles (no circular muscles),
parasitic, not segmented. Primarily reproduce
sexually, but some reproduce asexually through
parthenogenesis.
rotifera body symmetry
bilateral
rotifera tissue organization
triploblasts
rotifera circulatory system
none- diffusion
rotifera nervous system
Cerebral ganglia (brain) with
nerves extending through the body.
rotifera respiratory system
none- diffusion
rotifera digestive system
Alimentary canal, mouth and
anus.
rotifera embryonic development
protostome
rotifera general characteristics
Not truly segmented,
can reproduce sexually or parthenogenetically,
mostly freshwater environments. Draw food and
water into mouth by beating cilia.
