Quiz #2 Flashcards
Secondary Cavity
Internal cavity surrounding the gut that provides a “tube inside a tube” arrangement to the body
A-Coelomate
Organisms with no secondary cavity
Psuedocoelomate
Animals with a secondary cavity that is not entirely lined with a mesoderm layer
Coelomate
Animals with a true coelom. Fully lined with mesoderm layer
Characteristics of Psuedocoelomates
- Most have a pseudocoelom
- Most have an external cuticle
- Most have adhesive glands
Nematatoda
- Pseudocoelomate
- Roundworms
- No proto-nephrida
Rotifera
-Pseudocoelomate
-Wheel animals
Has protonephridia
Early development is related to 4 phenomena
- Pattern of cleavage
- Determinism of development
- Type of coelom formation
- Blastopore orientation
Two types of cleavage
Radial & Spiral
Radial cleavage
Non-determinant
Entrocoelus
Deutersomes
Spiral cleavage
Determinant
Schyzo-coelus
Protosomes
Annelids
- Segmented worms
- Prostomium and pygidium
- Complete digestive system
- Blood through dorsal and ventral vessels
- Dorsal brain
Oligochaeta
Earthworms Lack parapodia Uniform segments Deposit feeders No jaws/palps Hermaphroditic Cocoon with eggs
Hyrudeinea
Leeches Ecto-parasite Partially lost segmentation Hermaphroditic Cocoon and clitellum
Polychaeta
Unjointed appendages
chitin rods and setae
Palps, tentacles
Phyla closely related to Annelids
Sipuncula (peanut worms)
Echyura (spoon worms)
Pogonophora (beard worms)
Two unique characteristics of mollusks
- Radula
- 3 layer shell
Mollusc body plan
- mantle (& 3 layer shell)
- mantle cavity
- Head-foot + visceral mass
Molluscs
Open digestive system
Open circulatory system (except squid)
Meta nephridia
Gills or lungs in mantle cavity
Classes in annelids
Oligochaeta
Hyrudeinea
Polychaeta
Classes in Molluscs
Bivalvia
Gastropods
Cephalopoda
Bivalvia
clams, mussels Sedentary THESE DO NOT HAVE A RADULA nervous system underdeveloped trochophore larvae
Gastropoda
Snails, slugs
radula
internal fertilization
egg cases
Cephalopoda
squids, octopus, nautilus jet propulsion radula separate species external or internal fertilization highly developed nervous system
Arthropods
Jointed appendages exoskeleton reduced coelom open circulatory system no gills insects: malpighian tubes spiders: coxal glands crustaceans: green glands well developed nervous system
subphylums in arthropods
Trilobita
Chelicerata
crustacea
uniramia
Trilobita
trilobites
3 tagmata
1 pair antennae
Chelicerata
cephalothorax
chelicerae
padipalps
walking legs
3 classes in chelicerata
merostomata
picnogonida (sea spiders)
arachnida
crustacea
biramous appendages 2 pairs antennae mandibles and maxillae nauplius larvae (zoea & megalopae also larvae)
Myriapoda
centipedes, millipedes
2 part tagmata (head + trunk)
Malacostraca
class in crustacean decapods (crab + shrimp) 5 pairs of legs 1 pair antennae mandibles & maxillae
Hexapoda
uniramia six legs 1 pair antennae compound eyes malphigian tubes well developed nervous sytem
No metamorphosis
ametabolous
insects emerge egg looking like adult
wingless adults
Incomplete metamorphosis
hemi-metabolous egg, nymph, adult young lack wings adults fully form wings ex. dragonflies
Complete metamorphosis
holo-metabolous
egg, larvae, pupa, adult
ex. butterflies
adaptations in insects
- waxy cuticle
- most able to fly
- small size
- different mouthparts
