Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
42 Cards in this Set
- Front
- Back
|
Protosomes belong to which two Clades? |
Ecdysozoa and Spiralia |
|
|
Sprilia |
-Embryos develop in water (spiral cleavage) -live in water -move with cilia or muscle contractions -Two Clades: Platyzoans and Lophotrochozons
|
|
|
Platyzoans |
Most prominent group is flat worms -simple bodies, no circulitory or respiratory systems but complex reproductive system -includes marine and freshwater planarians (parasitic fluke worms and tapeworms |
|
|
Lophoptrochozoa |
Two defining characteristics: Trochophore-free living larva Lophophore- a horseshoe shaped crown of tentacles surrounds the mouth used for filter feeding. |
|
|
Ecdysozoa |
contains animals that molt exoskeleton Two large groups -Arthropods - Nematodes |
|
|
Flatworms |
-flatworms are ciliated -bodies are soft but solid aside from an incomplete digestive cavity -many are parasitic -others free-living-marine, freshwater, moist terrestrial -only one digestive cavity -no circulatory system- gas diffusion for transport -have an excretory and osmoregulatory system -metabolic wastes are excreted into gut and eliminated through the mouth -Simple nervous system- eye spot can distinguish light from dark -Reproduction-most hermaphroditic but also have capacity for asexual regeneration |
|
|
2 Major groups of Flatworms |
Free-living Tubellaria- common planaria in bio labs Parastic: Trematoda-flukes, attach inside host with suckers or hooks, may have 2 or more hosts in life, Schistosoma Cestoda(Ceromeromorpha)- tapeworms, adults hold onto inner wall of host intestine using scolex |
|
|
Lophotrochozoans-Phylum Mollusca |
-Second in diversity only to arthropods -includes snails. slugs, clams, octopi, and others - some have shells, some not -evolved in oceans and most still there -human food -Economically significant (pearls, mother of pearl) -Zebra muscles are pests |
|
|
Mollusk Body Plan |
Mantle- thick epidermal sheet, secrete shell if they have one Foot- primary means of locomotion, in cephalopods the foot is divided into arms or tentacles |
|
|
Mollusk Internal Organs |
-Coelom is very reduced -Digestive, excretory, and reproductive concentrated in a visceral mass -Gills in aquatic mollusks |
|
|
Mollusk Shell |
Protects against predators and adverse environments
Secreted by outer surface of mantle |
|
|
Radula |
-characteristic of most mollusks _rasping, tongue-like structure used in feeding -used to scrape algae -in predatory gastropods, modified to drill through clam shell -In Conus snails modified into harpoon with venom glands |
|
|
Mollusks waste removal |
Nephridia |
|
|
Mollusk Circulatory System |
Open circulatory system : Hemolymph sloshes around hemocoel -3 chambered heart -cephalopods have closed circulatory system |
|
|
Mollusk Reproduction |
- most are gonochoric (two distinct sexes) -most engage in external fertilization -trochophore- free swimming larval stage- -veliger -free swimming second larval stage only present in bivalves and most marine snails -both forms drift widely in the ocean |
|
|
Classes of Mollusks |
-Polyplacophora (chitons) -Gastropoda (limpets, snails and slugs) -Bivalvia- clams, oysters, scallops -cephalopodia- squids, octopi, cuttlefish, and chambered nautilus |
|
|
Class Polyplacophora (chitons) |
-marine mollusks that have oval bodies -8 overlapping dorsal calcareous plates -most chitons are grazing herbivores |
|
|
Class Gastropodia |
-Limpets, snails, slugs -Primarily marine group, some freshwater and only terrestrial mollusks -most have single shell- some have lost it -heads typically have a pair of tentacles with eyes |
|
|
Nudibranchs |
-marine snail without a shell -exposed gills -many secret distastefull chemicals -some extract nematocysts from cnidarian prey and transfer them to their body surface |
|
|
Class Bivalvia |
-Includes clams, scallops, muscles, oysters, and others -most marine some freshwater -no radula or distinct head -have 2 shells (valves) hinged together (abductor muscles counter hinge ligament) -water enters through inhalant siphon and exits through exhalant sipon |
|
|
Class Cephalopoda |
-more than 600 strictly marine species -active marine predators -only mollusk with closed circulatory system -foot has evolved into a series of arms with suctions cips and have beaklike jaws with toxic saliva -Largest relative brain sizes among invertebrates -highly developed nervous system -living cephalopods lack external shell (except chambered nautilus and squid and cuttlefish have internal shells) -jet propulsion using siphon -ink can be ejected from siphon -chromatophores allow for changing color in skin for camoflouge or communication - |
|
|
Lophotrochozoans-Nmertea (ribbonworms) |
-about 900 species of cylindrical to flattened very long worms -most are marine: a few species live in fresh water and humid terrestrial habitats -body plan resembles a flat worm - has complete gut -Rhynochocoel- fluid filled coloemic cavity |
|
|
Lophotrochozoans Phylum Annelida |
-segmented worms -body built of repeated units -allows for specialization - may not be monophyletic -roughly 12000 species occurring in many environments 2 classes- Polychaeta and Clitella |
|
|
Phylum Annelida Body plan |
- head has well-developed cerebral aglion -sensory organs in ringlike segments -many species have eyes -segments divided internally by septa ( each segment has excretory organs, a ganglion and locomotry structure -closed circulatory system -ventral nerve cord -each part of digestive tract specialized for different function |
|
|
Annelida Locomotion |
-coelmic cluid creates a hydrostatic skeleton - alternating muscle contractions allows complex movements - chateae- bristles of chitin found in most groups |
|
|
Annelida Circulatory system |
closed circulatory system- gas exchange by diffusion across body surfaces |
|
|
Annelida Excretory system |
nephrida similar to mollusks |
|
|
Class Polychaeta (Polychaetes) |
-Monophyly not well established -includes clamworms, sclaeworms, lugworms, sea mice, tubeworms, -Have paired parapodia on most segments (used in locomotion or gas exchange) *Chataetae on Parapodia -Most gonochoric -external fertilization -trochophore larva -Deep sea Tube worms- adults gutless, sulfur-oxidizing bacteria synthesize organic compounds used by worm -Found near hydrothermal vents |
|
|
Class Clitella |
-Oligochaeta -Hirudinea -Clitellums found in all members |
|
|
Earth worms (class Clitella) |
-head not well differentiated, -no parapodia, -few chaetae project from body wall, -hermaphroditic but cross fertilize, -Clitellum secretes mucus cocoon |
|
|
Leeches (Hirudinea) |
-occur mostly in fresh water -usually flattened dorsoventrally -hermaphroditic and cross-fertilization -suckers at both ends of body -no chaetae -some eat detritud, others suck blood |
|
|
Lophophorates |
-include two phyla of mostly marine animals (bryozoa and Brachiopodia) -Both characterized by lophophore -circular or U-shaped ridge around the mouth with 1-2 rows of ciliated tentacles -functions in gas exchange and feeding - may be convergent evolution -Phylogeny a puzzle |
|
|
Phylum Bryozoa |
-also called Ectoprocta or "moss animals" -Bryozoans are small and live in colonies -individuals secrete a tuiny chtiinous chamber -asexual reproduction occurs frequently by budding |
|
|
Phylum Brachiopodia |
-Brachiopods or lamp shells - have two calcified shells -Dorsal and ventral ( not lateral as in bivalves) - Lophophore lies on the body, between the shells |
|
|
Ecdysozoans Phylum Nematoda |
-vinegar eels, eelworms, and other roundworms -member are found everywhere, abundant and diverse -marine, freshwater, parasites, free-living -bilateral symmetry, covered by flexible, thick cuticle that molts as they grow |
|
|
Nematoda life |
-sexual reprodcution (most gonochoric) -sexual dimophrism-male smaller with hooked end -Eutely adults consist of fixed number of cells (Caenorhabditis elegans have 959 cells) -important to genetic developmental studies as it's the only animal whose complete develpomental cellular anatomy is known -Many are active hunters while other live inside bodies of other animals |
|
|
Nematoda as Pathogens |
-about 50 species cause human deisease |
|
|
-trichinella causes trichinosis
|
----Forms cucts in human muscle ----Infection from eating undercooked meat (notice cysts in the picture below |
|
|
Pinworms, ENterobius vermicularis |
-infects 30% of children in US -causes itchinf of the anus |
|
|
AScaris Lumbricoides -intestinal roundworm |
infects 1 in 6 worldwide -adult female can be 30 cm long -rare in areas with modern plumbing |
|
|
Serious tropical nematode diseases |
-Filariasis -eephantitis |
|
|
Arthropoda |
-by far the most successful animals (well over 1,000,000 species, 2/3 of all named species) -affect all aspects of humans life -diveded into 4 extant classes ---Chelicerata ---Crustacea ---Hexapoda ---Myriapoda |
