Protostomes pt.1 Flashcards
All remaining organisms are apart of what group?
Bilateria
What are the 4 types of bilateral symmetry?
- Anterior
- Posterior
- Dorsal
- Ventral
What are some characteristics of acoel flatworms?
- They lack a coelom
- Lack a permanent digestive system
- Thought to be related to Platyhelminthes but recent evidence shows that they are not as close as we once though.
What are 4 characteristics of lophotrochozoa?
- They grow by gradually adding body mass
- Spiral cleavage
- Many have free-living larva called trochophore.
- Some have a feeding structure called lophophore.
What are two characteristics of Ecdysozoa?
- Animals that molt
- Step-wise growth
Platyhelminthes include?
Flatworms
Mollusca include?
Snails, mussels, octopi, etc.
Annelida include?
Segmented worms (earth worms)
What are five characteristics of flatworms?
- Dorsoventrally flattened
- Incomplete gut, only one opening (Digestive system completely gone in tapeworms)
- Mouth midventral
- Acoelomate
- Most are hermaphroditic
What are the three parts of a flatworms body plan?
- Simple nervous system
- Complex reproductive system
- Excretory system
What are the 2 groups of flatworms?
- Free living (Tubellaria-marine, freshwater, and land planarians)
- Parasitic(Neodermata-flukes and tapeworms)
What are five characteristics of Mollusca?
- Coelomate, coelom reduced
- Complete gut
- Microscopic to huge
- Mostly marine
- Economically important
What are the four parts of a mollusk body plan?
- Mantel-thick epidermis layer which secretes shell
- Foot-muscular, used for swimming, digging, modified into tentacles or arms in some
3.Radula-chitinous teeth form rasping, tongue-like structure, lost in some - Shell-secreted by mantle, lost or reduced in some
What are the 4 characteristics of Mollusca-Polyplacophora?
- Marine mollusks with oval bodies
- 8 overlapping dorsal calcareous plates (shell)
- Mostly herbivores
- Muscular foot for attaching to rocks
What are five characteristics of Mollusca-Gastropoda?
- Primarily marine, some freshwater, only terrestrial mollusks
- Most with single shell, lost or reduced in some
- Pairs of tentacles with eyes
- Foot modified for locomotion/crawling
- Torsion-unique among animals (twisting of viscera during development)
What are some characteristics of Mollusca- Bivalvia?
- Clams, scallops, mussels, oysters, and more
- Mostly marine, some freshwater
- Freshwater mussels (Specialized parasitic larva-glochidia)
- Filter feeders
- Have two shells (valves) hinged together
- Laterally compressed
- Muscular foot for burrowing
What are some characteristics of Mollusca-Cephalopoda?
- Octopuses, squid, nautilus, cuttlefish
- Strictly marine
- Active predators
- Highly developed nervous system(eyes similar to ours developed, separately)
- Foot highly modified
- Radula inside beak-like jaws
- External shell lost in most (present in chambered nautilus, internal in squid and cuttlefish)
- Chromatophores-change skin color for camouflage and communication
- Ink sac-ink release as a defense
