Chapter 33: Protostomes

What type of body cavity do flatworms have?

Acoelomate

Are flatworms triploblastic or diploblastic?

Triploblastic

What type of symmetry do flatworms have?

Bilateral symmetry

Do flatworms have an incomplete or complete digestive tract?

Incomplete

Do flatworms have circulatory or respiratory systems?

No, they rely on diffusion

What type of nervous system do flatworms have?

Ladder-like nervous system with paired nerve cords

What are flame cells used for in flatworms?

Osmoregulation and excretion

Are most flatworms parasitic or free-living?

Many are parasitic

What class do flukes belong to?

Trematoda

Do flukes have complex life cycles?

Yes

What organ do flukes use to attach to hosts?

Suckers

What class do tapeworms belong to?

Cestoda

Do tapeworms have a digestive system?

No

What is the head of a tapeworm called?

Scolex

What are tapeworm body segments called?

Proglottids

Are tapeworms hermaphroditic?

Yes

What type of body cavity do nematodes have?

Pseudocoelom

Do nematodes have complete or incomplete digestion?

Complete

What covers the body of nematodes?

Cuticle

Do nematodes molt?

Yes, they undergo ecdysis

Do nematodes have circular or longitudinal muscles?

Longitudinal only

What type of movement do nematodes have?

Thrashing movement

Do nematodes have circulatory or respiratory systems?

No, rely on diffusion

Are nematodes usually dioecious?

Yes

What phylum includes clams, snails, slugs, octopus, and squid?

Mollusca

Are mollusks coelomates?

Yes

What are the three main parts of the mollusk body plan?

Foot, visceral mass, mantle

What does the mantle secrete?

Calcium carbonate shell

What structure houses gills in mollusks?

Mantle cavity

What is the rasping feeding structure in most mollusks?

Radula

Which mollusk class lacks a radula?

Bivalvia

Do mollusks have open or closed circulatory systems?

Mostly open, but cephalopods have closed

What excretory structure do mollusks have?

Nephridia

What type of larval stages do mollusks have?

Trochophore and veliger

Do mollusks undergo spiral cleavage?

Yes

What class includes snails and slugs?

Gastropoda

What is torsion in gastropods?

Rotation of mantle cavity and anus to the anterior

What is coiling in gastropods?

Spiral winding of the shell

What do nudibranchs steal from cnidarian prey?

Nematocysts

What class includes clams, mussels, scallops, and oysters?

Bivalvia

Do bivalves have a head?

No

Do bivalves have a radula?

No

How do bivalves feed?

Filter feeding with siphons and cilia on gills

Are bivalves mostly sessile?

Yes

What class includes squid, octopus, cuttlefish, and nautilus?

Cephalopoda

Do cephalopods have open or closed circulatory systems?

Closed

What has the foot evolved into in cephalopods?

Arms and tentacles

Do cephalopods have a well-developed brain and eyes?

Yes

What method of movement do cephalopods use?

Jet propulsion

What pigment cells allow cephalopods to change color?

Chromatophores

Do cephalopods have external shells?

Only nautilus

Do cephalopods have direct development?

Yes

Are annelids segmented?

Yes

What divides annelid segments internally?

Septa

What are chitin bristles in annelids called?

Chaetae or setae

What type of skeleton do annelids use?

Hydrostatic skeleton

Do annelids have complete digestion?

Yes

What structures are part of annelid digestion?

Pharynx, esophagus, crop, gizzard, intestine

Do annelids have open or closed circulatory systems?

Closed

Do annelids have multiple "hearts"?

Yes, about 10 muscular vessels

Where does respiration occur in annelids?

Across the body surface

What excretory structure do annelids have?

Nephridia

What is the annelid nervous system like?

Anterior ganglion and ventral nerve cord

What are the two new annelid classifications?

Errantia and Sedentaria

Which group includes most bristle worms?

Errantia

Which group includes tubeworms, earthworms, and leeches?

Sedentaria

Do bristle worms have parapodia?

Yes

Are bristle worms gonochoric or hermaphroditic?

Gonochoric

Do bristle worms have trochophore larvae?

Yes

What annelid class includes earthworms and leeches?

Clitellata

What is the clitellum used for?

Mucus production during reproduction and cocoon formation

Are earthworms hermaphroditic?

Yes, but they cross-fertilize

Do earthworms have eyes?

No

Do earthworms have few or many chaetae?

Few

What type of development do earthworms have?

Direct development

Do leeches have chaetae?

No

Are leeches hermaphroditic?

Yes

Are leeches mostly freshwater?

Yes

What substances does leech saliva contain?

Anticoagulants, vasodilators, anesthetics

What medical use do leeches have?

Reducing pooled blood and promoting capillary flow

How should a leech be removed?

Slide an object under it gently, do not rip off

What is the most successful phylum in the animal kingdom?

Arthropoda

What are arthropod bodies covered by?

Exoskeleton of chitin

What does the exoskeleton prevent?

Water loss

What must arthropods do to grow?

Molt (ecdysis)

What are the three main arthropod tagmata in insects?

Head, thorax, abdomen

What are fused head and thorax called?

Cephalothorax (prosoma)

What are jointed appendages used for?

Walking, feeding, sensory, reproduction

What is the arthropod nervous system?

Ventral nerve cord + brain of fused ganglia

What are compound eye units called?

Ommatidia

What do simple eyes (ocelli) detect?

Light and dark

Do arthropods have open or closed circulatory systems?

Open

Do arthropods use their blood for oxygen transport?

Usually no

What respiratory system do insects use?

Tracheae and spiracles

What limits arthropod body size?

Oxygen diffusion limits of tracheal system

What is the main excretory organ in insects?

Malpighian tubules

What nitrogenous waste do insects produce?

Uric acid or guanine

What subphylum includes spiders, scorpions, ticks, and mites?

Chelicerata

What mouthparts do chelicerates have?

Chelicerae

What structures sit behind chelicerae?

Pedipalps