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full sections: 32.1 33.1 33.2

definition of animals

multicellular eukaryotes who are heterotrophic and develop tissues from embroyonic layers

# extant species

1.3 million

# phyla of invertebrates and % of all animals

35, making of 95 % of all animals


development of distinct anterior end (head)


virgin birth, no mating. 2n mother gives 2n CLONE children


same individual has male and female parts, generally each part still gives sperm to another


flagelleted cells for help in feeding, the COLLAR CELLS of sponges; closely resemble chinoflaggates-type of protist animals are closely related to

body plan

a set of morphological and developmental traits, integrated into a functional whole-the animal.


the concentration of sensory equipment at a body's anterior end, including the central nervous system/brain. Evolutionary trend typical of bilaterals


the formation of tissue layers in an embryo


the germ layer covering the surface of the embryo, giving rise to the covering of the animal


innermost germ layer, lining digestive tube


a thrrd germ layer present in all bilaterals which lies between the ectoderm and the endoderm

body cavity/coelom

a fluid or air-filled space separating the digestive tract from the outer body wall


development begins with spiral, determinate cleavage; coelom forms from splits in the mesoderm; and the mouth froms from the blastopore


Development is radial, indeterminate cleavage; the coelom forms from mesodermal outpocketings of the archenteron; and the mouth forms from secondary openings


derived from shared derived characteristics

4 Points of phylogeny agreement

(1) all animals share a common ancestor (2) sponges are basal animals (3) most animal phyla belong to the bilateral clade (4) chordates and some other phyla belong to the clade Deuterostomia

Sponges (Calcaea and Silicea)

sessile animals lacking tissues, suspension feeders, hermaphrodites. marine and freshwater.


corals, jellies, and hydras. radially symmetrical w/ grastrovascular cavity & ONE OPENING, either polyps or medusa. have cnidocytes w/nematocysts.


Flatworms; bilateral symmetry, aceolomates, with a central nervous system. no circulation. ONE OPENING= thorax. have flame cells/protonephridia. HERMAPHRODITES or fission


have a soft body generally protected by a hard shell


annelids/segmented worms. eat dirt for bacteria and fungi nutrition, then out the anus as castings. means "little rings"


roundworms; terrestrial and aquatic, parasitic and free living. have a touch CUTICLE coating body


most species diversity, insects, crustaceans, and arachnids. segmented exoskeleton and jointed appendages


sand dollars, sea stars, and sea urchins, aquatic, bilateral as larva but not as adults. using internal canals to pump water throughout body


90% are vertebrates, also includes lancelets, tunicates and hagfish invertebrates

suspension feeders

capture food particles syspended in the water passing through their body


large opening which water and undigested food flows out of the sponge


central cavity of sponge which water and particles are drawn into


a gelatinous region of the sponge separating the 2 tissue layers, where fertilization occurs


organelles in cnidocytes which sting the cnidarian's prey


both ployp and medusa stages in cnidarians; polyp stage often colonial (only one to include some freshwaters, all else marine) EX OBELIA


medusa only cnidarians


box shaped medusa


polyp only cnidarians. sea anemones and coral


typical flatworm, one opening is thorax, has light sensitive eyespots and lateral flaps which detect specific chemicals. NOT a parasite


a straplike rasping organ used by molluscs to scrap up food


class of molluscs w/ 8 dorsal plates


class of molluscs including snails and slugs, have a spiraled shell into which the animal can retreat when threatened. marine, land and aquatic.


class of gastropods with a shell divided into two halves. no distinct head, no radula, trap food particles in mucus. can have many eyes. clams, musscles, and scallops


class of gastropods, active predators with tentacles, shell is reduced and internal. feet are at the head. only molluscs with a closed circulatory system and good sense organs, complex brain. have camera type eye.


annelids including earthworms and aquatics, earthworms are hermaphrodites


vectors of many disease, used to drain blood. have bladelike jaws to slit the skin, use hirudin to stop blood coagulating near incision


roundworms which transport nutrients through fluid in the pseudocoelom and reproduce sexually


means "jointed feet", have segmented bodies, a hard exoskeleton, and jointed appendages. Evolved in the sea and later lived on land.

Arthropod circulatory & respiratory system

open, fluid called hemolymph is pumped by heart through short arteries and into sinuses. Specialized gas-exchange organs have evolved, most aquatics have gills and insects have tracheal systems


clawlike feeding appendages which serve as pincers or fangs of cheliceriforms


think fangs, they have a chelicerae, an anterior cephalothorax anda posterior abdomen, lack antenna. 8 legs


a pair of appendages functioning in sensing, feeding, or reproduction; and 4 pairs walking legs


terrestrial arthropods with mandibles, among the earliest on land, include centipes and millipedes

complete/complex metamorphosis

85% of insects, egg -> larva -> pupa -> adult

simple (incomplete)

egg-> nymph -> adult (ex grasshopper)

pupa stage

as larva tissues break down, it becomes an adult


first flying animals, internal fertilization

abdomen organ systems

digestive organs and gonads


marine and freshwater, only arthropods w/ 2 pair antennae, large species have gills, small respirator across membrane,


10 legs, cuticle hardened by calcium carbonate, ex. lobster, crayfish, crab


planktonic crustaceans, most numerous of all animals


"spiny skin", prickly from skeletal bumps and spines, have unique water vascular system branching into tube feet. marine

Sea starts

star shaped echinoderms with multiple arms; mouth directed to substrate. Gripping due to adhesive chemicals. Feed by opening bivalve and inserting stomach into the shell

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