Protostomes Lecture Review

Flashcards covering vocabulary terms from the Protostomes lecture notes.

Protostomes

Develop the mouth from the blastopore.

Protostome Development

A type of embryonic development where the mouth develops from the blastopore.

Determinant Cell Fate

Embryonic cell fate is determined early in development.

Protostome Coelom Formation

Cells move apart to form the coelom.

Lophotrochozoa and Ecdysozoa

Two major clades within Protostomes.

Lophotrochozoa

Embryos develop using spiral cleavage

Trochophore

Free- living larval stage of Lophotrochozoa

Lophophore

Horseshoe-shaped crown of ciliated tentacles surrounds the mouth used in filter-feeding of Lophotrochozoa.

Ecdysozoa

Animals that molt

Exoskeleton

External skeleton of Ecdysozoa

Arthropods and Nematodes

Two large groups of Ecdysozoa

Platyhelminthes

Phylum containing flatworms.

Flatworms

Ciliated, soft-bodied animals with incomplete digestive cavity.

Flatworm Digestive Features

Only one opening to digestive cavity.

Pharynx Function in Flatworms

Ingestion and tearing of food into small bits via muscular contractions.

Diffusion in Flatworms

How gas is transported through flatworms.

Tapeworms

Parasitic flatworms that lack digestive systems and absorb food directly through body walls

Flatworm Excretory System

Network of fine tubules runs through body for excretion and osmoregulation.

Flame cells

Located on the side branches of flatworm's excretory system

Flatworm Nervous System

Anterior cerebral ganglion and nerve cords

Eyespot

Ability to distinguish light from dark

Hermaphroditic

Organisms that have both male and female reproductive organs.

Flatworm Reproduction

Asexual regeneration.

Subphylum Neodermata

Includes the parasitic flatworms

Trematoda and Cercomeromorpha

Two subgroups of parasitic flatworms

Trematoda

Flukes

Fluke Attachment

Attach within host body by suckers, anchors, or hooks

Miracidium, sporocyst, redia, and cercaria

Stages of fluke life cycle

Clonorchis sinensis

Liver Fluke

Schistosoma

Blood flukes

Cercomeromorpha

Tapeworms

Tapeworm Adult

Hangs onto inner wall of host intestine using scolex

Proglottids

Complete hermaphroditic unit, containing both male and female reproductive organs

Beef tapeworm, Taenia saginata

Frequent human parasite from eating uninspected rare beef

Rotifera

Bilaterally symmetrical, unsegmented pseudocoelomates.

Corona

Wheel Animals.

Corona Function

Conspicuous ring of cilia at anterior end used for locomotion and sweeping food into the mouth.

Mollusca

Phylum that is second in diversity only to arthropods

Mantle

Thick epidermal sheet that bounds mantle cavity and secretes shell.

Foot

Primary means of locomotion for many mollusks.

Ctenidia

Gills in aquatic mollusks.

Mollusk Shell

Protect against predators and adverse environments

Shell Layers

Calcium carbonate layers of shell.

Pearl Formation

Process of coating foreign object with nacre to reduce irritation.

Radula

Rasping, tongue-like structure used in feeding

Nephrostomes

Cilia-lined openings of nephridia

Mollusk Circulation

Open circulatory system where hemolymph sloshes around hemocoel

Gonochoric

Individuals are either male or female

Trochophore (Mollusks)

Free-swimming larval stage of mollusks

Veliger

Second free-swimming larval stage found in bivalves and marine snails

Gastropoda

Limpets, snails, slugs

Torsion

Unique among animals; mantle cavity and anus are moved from the posterior to the front

Coiling

Spiral winding of the shell

Bivalvia

Clams, oysters, scallops

Inhalant siphon and exhalant siphon

Water enters through and exits through _

Cephalopoda

squids, octopuses, cuttlefishes, and chambered nautilus

Cephalopods

The only mollusk with closed circulatory system

Chromatophores

Changing skin color for camouflage or communication

Annelida

Segmented worms

Sensory organs

Ring-like segments

Chaetae

Bristles of chitin found in most groups of annelids

Errantia and Sedentaria

Annelid Clades

Sedentaria

Little movement; may burrow or live in tubes; may feed using tentacle or may filter-feed.

Riftia

Adults are gutless; sulfur-oxidizing bacteria housed on body.

Clade Clitellata

Clitellum found in all members

Clitellata

(Earthworms) Head not well differentiated; no parapodia; few chaetae project from body wall.

Earthworms

Term for hermaphroditic that cross-fertilize

Clitellum

Secretes mucus cocoon

Leeches

Occur mostly in freshwater; usually flattened dorsoventrally; hermaphroditic/cross-fertilization.

Nematoda

Flexible, thick cuticle that is molted as they grow

Stylets

piercing organs near mouth

Sexual dimorphism

Male smaller with hooked end

Cellular composition

Adults consist of a fixed number of cells

Trichinella

forms cysts in muscles.

Pinworms

Causes itching of the anus

Arthropoda

By far the most successful animals.

Chelicerata, Crustacea, Hexapoda, and Myriapoda

Arthropoda classes

Chelicerata

Anterior appendages are specialized as pincers or fangs

Crustacea

Mouthparts are mandibles; appendages are biramous; the head has two pairs of antennae.

Hexapoda

Mouthparts are mandibles; the body consists of three regions: a head with one pair of antennae, a thorax, and an abdomen; appendages are uniramous

Exoskeleton of Arthropods

Made of chitin and protein; protects against water loss.

Nervous system of Arthropods

Double chain of segmented ganglia.

Simple eyes, or ocelli

May be in addition to compound eyes; have single lenses; distinguish light from darkness

Respiratory system of Arthropods

Terrestrial arthropods use tracheae

Malpighian tubules

Eliminates nitrogenous wastes as concentrated uric acid or guanine. Efficient conservation of water

Class Chelicerata

Most anterior appendages called chelicerae.

Order Araneae (Spiders)

Silk protein forced out of spinnerets found on the posterior of the abdomen

Order Acari (Mites and Ticks)

Cephalothorax and abdomen are fused into an unsegmented ovoid body.

Class Crustacea

Have three tagmata