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INVERTEBRATES Introduction: Animalia is the largest of the five kingdom system, with over one milli on species. It has an extreme variety of shapes, colors, and sizes. It is made up of eukaryotic, m ulticellular, heterotrophic organisms that are either aquatic or terrestrial and reproduce sexually or asexually. Invertebrates are a type of animal that have no backbone. They make up for about 97% of the animal kingdom. Some invertebrates are earthworms, butterflies, jellyfish, and giant squid. There are two kinds of invertebrates, lower and higher. Lower invertebrates are further behind in evolution, they are very soft and squishy and more vulnerable to predators. Higher invertebrates ar e further along in evolution, they are tougher and can be considered less vulnerable. Porifera: Gen eral Characteristics: oSponges are hollow cylinders that are closed at the bottom and have an openin g at the top called an osculum. oThe cylinder is lined with special collar cells (choanocytes) which by beating their flagella pulls water into the sponge through pores and canals and circulates throu gh the osculum. oSponges live a sessile lifestyle, so when collar cells pump water into sponge they also screen bacteria, unicellular algae, protozoans, and bits of organic matter out of it and engulf it. Known as filter feeding. oWhile circulating water, wastes are excreted into the water as it ex its the osculum. oFor support some sponges have simple skeletons made of protein fibers called spong in. Others have skeletons made of tiny, hard particles called spicules. oSponges reproduce asexuall y by forming small buds that break off and live seperatley. And sexually by sending sperm into pore s of another sponge. Evolutionary Development: Porifera represents the least evolutionarily advance d animals of the animal kingdom. Classes: oCalcarea © they have spicules of calcium carbonate. oHex actinella © They have spicules of silicon dioxide. oDemospongiae © They have spongin or a combinatio n of spongin and spicules of silicon dioxide. oSclerospongiae © They have spongin plus spicules of s ilicon dioxide and calcium carbonate. Didja Know? .....that sponges come in every color of the rain bow and also come in many varied forms such as mossy mats, cacti, blobs of fungus, and tall tubes. 10 Questions Review: 1.What is the opening called at the top of a sponge? An osculum. 2.What is anot her name for collar cells? Choanocytes. 3.Sponges are sessile, what does this mean? It means that th ey attach themselves firmly to surfaces and do not move. 4.What is the main diet of a sponge? Bacter ia, unicellular algae, protozoans, and bits of organic matter. 5.What is a sponge's method of eating called? Filter feeding. 6.What are the two skeletons of porifera known as? Spongin and spicule. 7.W hat are a sponge's means of reproduction? Sexually and asexually by regeneration. 8.What are the fou r classes of porifera? Calcarea, hexactinella, demospongiae, and sclerospongiae. 9.What kind of inve rtebrate is a sponge, lower or higher? They are lower, because they are further behind in evolution. 10.What do collar cells do to get water pumping? They rapidly whip their flagella in every which wa y direction. Cnidaria: General Characteristics: oCnidarians are either polyp (vase shaped) or medus a (bell shaped). Polyp is specialized for a sessile life and medusa for swimming. oThey consist of two cell layers © the endoderm and the ectoderm, between them is a jelly like substance called mesog lea. oTo feed, their tentacles capture prey and parylize it with coiled stingers called nematocysts, located in the cnidocytes (stinging cells which characterize cnidarians). oAfter capturing prey it' s drawn into their mouth, called a gastrovascular cavity (hollow gut), enzymes break up food and spe cialized cells lining cavity absorb it. oWastes and undigested foods are expelled through mouth. oCn idarians have radial symmetry. Evolutionary Development: Cnidarians date back 540 © 600 million yea rs ago. They split off from porifera when they developed layered skin, or layers of cells. Classes : oHydrozoa © This includes polyps, medusae, and species that alternate between the two. oScyphozoa © They're the true jellyfishes, spending most of the life cycle as medusae. oAnthozoa © They live on ly as polyps and include anemones and corals. Didja Know? .....that the two different forms of Cnid arians, medusa and polyp, resulted from a different arrangement of the same body parts. 10 Question Review: 1.What is the difference between polyp and medusa? Polyp is vase shaped and medusa is bell shaped. 2.What are polyp and medusa specialized for? Polyp is made for a sessile life, and medusa fo r swimming. 3.What are the three layers of a cnidarian? The ectoderm, mesoglea, and the endoderm. 4. What are the coiled stingers on their tentacles called? Nematocysts 5.What is the hollow gut of the cnidarian known as? Gastrovascular cavity. 6.What kind of symmetry do they have? They have radial sy mmetry. 7.What stinging cells characterize cnidarians? Cnidocytes. 8.What do anthozoa live their ent ire life as? Polyps. 9.Name the three classes of cnidaria! Hydrozoa, scyphozoa, and anthozoa. 10.How do they rid of wastes and undigested foods? They send them back into the mouth. Platyhelminthes: G eneral Characteristics: oThey are bilaterally symmetrical. oThey lack respiratory and circulatory sy stems. oThey're flat. oMostly aquatic. oTheir soft bodies cause them to be unprotected from predator s and dehydration. oFlatworms are hermaphroditic and they can reproduce sexually and asexually. Sex ually when two planarians simultaneously fertalize eachother and asexually by regeneration. oThey ar e capable of fertalizing their own eggs, but they usually dont. Evolutionary Development: Flatworms are the first animals to have bilateral symmetry, cephalization, and three tissue layers. Classes: oTurbellaria © They live in marine environments, are hermaphroditic, and are free living. oTrematod a © Parasitic flukes that are oval shaped, 1cm long, and have two sucker mouths. oCestoda © Parasiti c tapeworms that have hooks and suckers, they may grow as long as 12m. Didja Know? .....that planar ians feed by extending a tube, the pharynx, out of their mouth and sucking up food, kind of like a s traw. 10 Question Review: 1.What's the symmetry of a planarian? They are bilaterally symmetrical. 2 .What systems do planarians lack? A circulatory and respiratory system. 3.What is the body type of a planarian? Planarians are flat, soft, and very squishy. 4.Are they hermaphroditic? Yes. 5.Can they fertalize themselves? Yes, they can, but they usually dont. 6.How do they sexually reproduce? When two planarians simultaneously fertalize eachother by absorbing eachother's sperm. 7.How do they repr oduce asexually? By regeneration. 8.What are the three classes? Turbellaria, trematoda, and cestoda. 9.What are the only free living planarians? Planarians of the class turbellaria. 10.What is the pha rynx? A tube, that in some animals extends out of the mouth, and functions in eating. Nematoda: Gen eral Characteristics: oThey have round, slender bodies that taper at each end. oMost are covered wit h a protective, flexible cuticle. oThey range from less than 1mm in length up to 120cm. oTheir diges tive tract has two openings. oThey have an anterior mouth and posterior anus. oParasitic in both pla nts and animals, but most are free living. oThe male is smaller than the female. oMost varieties of roundworms aren't hermaphroditic. oThey're bilaterally symmetrical. Evolutionary Development: Round worms are the first animals to have different sexes. They have developed adaptations for parasitism . Classes: oSecernentea © They're somewhat porous and oval or cleft like. oAdenophorea © Character ized by reduced or absent caudal papillae and an excretory system lacking latoral canals. These org anisms are usually infective to their final host. Didja Know? .....that the most common roundworms are the ascaris, the ancylostoma, the necator, and the trichinella. 10 Question Review: 1.What type of body do roundworms have? They are long, slender, and tapered at each end. 2.What is the range in size for roundworms? They range from 1mm in length up to 120cm. 3.How many openings do their digest ive tract have? It has two. 4.What is the placement of their mouth and anus? Their mouth is anterior and their anus is posterior. 5.What kind of lifestyle do most nematodes live? Most are freeliving, but some are parstitic in both plants and animals. 6.Is the male larger than the female? No, the fem ale is larger than the male. 7.What is the roundworms symmetry? They are bilaterally symmetrical. 8. Is it true that most roundworms aren't hermaphroditic? Yes, it sure is true. 9.What animals are the first to have different sexes? Nematodes. 10.What are the two classes of nematodes? Secernentea and adenophorea. Rotifera: General Characteristics: oRotifera are transparent, free-swimming, microscop ic animals. oThey live in marine or fresh-water environments. oThey are between 100 and 500 nanomete rs long, the female is much larger than the males. oRotifers have a crown of cilia around their mout h, while feeding they use their cilia to sweep food into their mouth. This food moves through the p harynx and into the mastax, a muscular organ that chops up food. oThey feed on unicellular algae, ba cteria, and protozoa. oThey have no skeleton, they maintain their shape bye the hydrostatic pressure within the pseudocoelum. Evolutionary Development: The crown of cilia that surrounds the rotifer's mouth is an adaptation for free living. Classes: oDigononta © They have paired ovaries. There's t wo orders, bdelloidea and selsonidea. oMonogononta © There are free-swimming and sessile forms. Fem ales posses one ovary. Males are only present for several days out of the year. It has three orders : collothecacea, flosculariacea, and ploimidia. Didja Know: .....that under a microscope while a ro tifer beats it's cilia it apears as if the cilia are rotating wheels. 10 Question Review: 1.What ty pe of environment do rotifera live in? Marine and freshwater. 2.What size do rotifera range in? Anyw here from 100-500 nanometers. 3.Who's larger, the male or the female: Females are much larger than t he males. 4.What structure on rotifera is an adaptation for free-living? The crown of cilia around t heir mouth. 5.Explain the rotifer's feeding process! They sweep food into their mouth with the cilia , it then passes through the pharynx, and on into the mastax. 6.What do rotifera eat? They eat unice llular algae, bacteria, and protozoa. 7.How do rotifera maintain their shape? Since they have no ske leton, they maintain their shape with hydrostatic pressure within the pseudocoelum. 8.What are the t wo classes of rotifera? Digononta and monogononta. 9.What are the two orders of digononta? Bdelloide a and seisonidea. 10.What are the three orders of monogononta? Collothecacea, flosculariacea, and pl amida. Annelida: General Characteristics: oThey all have true coelums. oTheir body is divided into many segments. This is known as metamerism. oMost annelids have external bristles called setae, whic h function in movement. oSome have fleshy appendages called parapodia. oTerrestrial and aquatic envi ronments. Evolutionary Development: The anterior segment of earthworms reflect the cephalization th ats an adaptation for burrowing. They also have gizzards, which is adapted for burrowing as it grin ds up the soil. Classes: oOligochaeta © They have over 100 segments (metameric units). To move, th e earthworm anchors it's posterior setae and elongates forward then anchoring its anterior setae and pulling it's posterior forward. They burrow and feed on soild and organic matter at the same time. Food passes from pharynx to the esophogus, to the crop, then to the gizzard. They have a closed c irculatory system. Oxygen and carbon dioxide are diffused directly across the skin, this requires m oist skin. They are hermaphroditic, though they are not capable of fertalizing their own egg. oPoly chaeta © They live in all marine habitats. Some are free swimming predators, somw burrow and eat se diment, and other pump water through their body and scour floor with tentacles. oNirudinea © Theyre leeches and have no setae. They have suckers on each end of their body. Most live in calm bodies o f freshwater. Didja Know? .....that leeches are often used by doctors in the reattachment of a body part so that proper blood flow will take place which will allow the operation to be successful. 10 Question Review: 1.What kind of coelum do they have? All annelids have true coelums. 2.Annelid's bo dies are divided into many segments, what is this known as? This is known as metamerism. 3.What are their external bristles known as? Setae. 4.What do the setae function in? They function in movement. 5.What is parapodia? They are the fleshy appendages of an annelid. 6.What kind of environments do t hey live in? Terrestrial and aquatic. 7.What are the three classes? Oligochaeta, polychaeta, and nir udinea. 8.What class do earthworm's fall in? Oligochaeta. 9.What animals make up the class nirudinea ? Leeches. 10.What is a gizzard? A structure adapted for burrowing as it grinds up soil. Mollusca: General Characteristics: oThey have very soft bodies, but most mollusks have a shell that protects a nd conceals their soft bodies. oSome are sedentary filter feeders and other s are predatory. oSquids and octopuses move by jet propulsion. oAll mollusks have a true coelum. oThey have three main body parts: the muscular foot, the head, and the visceral mass. oThey have organ systems for circulations , respiration, digestions, excretion, nerve impulse conduction, and reproduction. oThey are bilatera lly symmetrical. oUsually have one or more shells. Evolutionary Development: Mollusks adapted the s hell because it protected their soft body from predators. But the shell posed a problem because it reduced the area available for gas exchange, this problem was fixed when a new adaption evolved, the gills. Classes: oPolyplacophora © Also called chitons. Animals of the seashore, they live mostly on rocks. Their shells are divided into four seperate, overlapping plates. oGastropoda © They have single shells. They have torsion, the visceral mass twists 180 degrees in relation to the head. Th is twisting brings the mantle cavity to the animal's front, this allows the animal to draw it' head into the mantle cavity when endangered. oBivalvia © They are sessile and filter food from the water. They have a shell with two valves and a muscular foot. This foot acts as an anchor and holds it d own in the sand. oCephalopoda © They have a "head-foot", meaning a large well developed head with ma ny tentacles. They are free swimming and live a predatory existence. Their tentacles have strong s uckers, they kill and eat their prey with the help of the radula and a sharp beak. They have a clos ed circulatory system. Didja Know? .....that as a result from torsion during larval development, th e sail developed an anus above it's head. 10 Question Review: 1.What type of body do mollusks have ? Soft bodies, though most have protective shells. 2.How do mollusks feed? Some are filter feeders a nd others are predatory feeders. 3.What kind of coelum do they have? A true coelum. 4.What are their three main body parts? Muscular foot, head, and the visceral mass. 5.What are squids and octopuses means of movement? They move by jet propulsion. 6.What is a mollusks symmetry? They have bilateral s ymmetry. 7.What kind of organ systems do they have? Circulatory, respiratory, digestive, excretory, nerve impulse conduction, and reproduction. 8.What are the four main classes? Polyplacophora, gastro poda, bivalvia, and cephalopoda. 9.What kind of circulatory system do cephalopoda have? Closed circu latory system, which means that they have veins, arteries, and capillaries. 10.How does bivalvia use it's muscular foot? It uses it as an anchor to be held into the sand, because they're sessile creat ures. Arthropoda: General Characteristics: oAll have jointed appendages (extensions of the body, in cludes legs and antennae). oSegmented body. A pair of appendages on each segment, though evolution has changed this in some species. oThey have exoskeletons. oThey have ventral nervous system, and op en circulatory system, a digestive system, and specialized sensory receptors. oIn order for arthropo ds to grow they must periodically shed and form a new exoskeleton, this process is known as molting. Evolutionary Development: Evolved more than 600 million years ago. Arthropods all evolved from a common ancestor. The evolution of arthropods shows them having less and less segments as time goes on. Classes: oTrilobita © extinct organisms called trilobites. oCrustacea © Shrimp, lobsters, crabs , barnacles, ciadocerans, ostracods, crayfish, water fleas, and copepods. oChelicerata © spiders, sc orpions, ticks, mites, sea spiders, and horseshoe crabs. oUniramia © The only group that has evolved on land, it includes centipedes, millipedes, and insects. Didja Know? .....that the exoskeleton is made mostly of protein and the tough carbohydrate chitin. The waxy outer layer repels water and pr events desiccation, the hard middle layer provides important protection, and the flexible inner laye r allows animals to move freely. 10 Question Review: 1.What are appendages? Extensions of the body, like legs and antennae. 2.What kind of protection do arthropods have? They have an exoskeleton. 3.W hat different systems do they have? A ventral nervous system, an open circulatory system, a digestiv e system, and specialized sensory receptors. 4.What must arthropods do in order to grow? They must m olt. 5.What is molting? The process by which arthropods shed and form a new exoskeleton. 6.About how long ago did they evolve? More than 6 million years ago. 7.What are the four classes of arthropoda? Trilobita, crustacea, chelicerata, and uniramia. 8.Which class is extinct? Trilobita. 9.Which is th e only group to have evolved on land? Uniramia 10.Which animals are in the class of uniramia? Centip edes, millipedes, and insects. Insecta: General Characteristics: oBody has three main parts: the he ad, thorax, and the abdomen. oThe head has one pair of antennae. oThe thorax has three pairs of join ted legs, and in many species, one or two pairs of wings. oThe abdomen is divided into eleven segmen ts. It has no legs or wings attached to it. oThey also have exoskeletons, jointed appendages, and a segmented body. oThere are three main categories that set different insects apart: structural varia tions, physiological variations, and behavioral variations. oThey have an open circulatory system. o They do not breath with lungs or gills, but with tiny openings on their abdomen and thorax, called s piracles. Evolutionary Development: Adaptations such as those of other arthropods have allowed inse cts to be successful. But they have also adapted other characteristics of their own. Didja Know? . ....that the reproductive organs of both male and female grasshoppers are located in their abdomen. 10 Question Review: 1.What are the three main parts of an insect? The head, thorax, and the abdomen . 2.How many antennae do they have? One pair. 3.How many pairs of legs do they have? Three pairs. 4. How many segments is their abdomen divided into? Eleven segments. 5.What three main categories set d ifferent insects apart? Structural variations, physiological variations, and behavioral variations. 6.What kind of circulatory system do insects have? They have an open circulatory system. 7.What do t hey breath with? Spiracles. 8.What are spiracles? They're tiny openings on the abdomen and thorax th at insects breath through. 9.What do insects have as well as all arthropods do? Exoskeleton, jointed appendages, and a segmented body. 10.If an insect has wings, what are they attached to? They are at tached to the thorax. Echinodermata: General Characteristics: oThey inhabit all kinds of marine env ironments. oThey range from 1cm to 1m in diameter. oThey often have brilliant coloring. oMost underg o metamorphosis from a free-swimming, bilaterally symmetrical larva to a bottom dwelling adult with radial symmetry. oMost have five radii, known as pentaradial symmetry. oThey have an endoskeleton. o They have a water-vascular system, which is a network of water filled canals. oThey have tube feet t hat aid in movement, feeding, respiration, and excretion. oNo circulatory, respiratory, or excretory systems. oHave a nervous system, but no head or brain. oThere are two sexes and they reproduce sexu ally or asexually. Evolutionary Development: Echinoderms have existed over 500 million years. They evolved from bilaterally symmetrical ancestors. Scientists believe echinoderms used to be sessile. Classes: oCrinoidea © They are sessile and have a long stalk attached to a rock or the sea bottom. They have five extending arms which branch out into many more arms. They can have as much as 200 a rms. oAsteroidea © These are sea stars or starfish. They prey on oysters, clams, and other organism s that are used as food by humans. oOphiuridea © These are basket and brittle stars. Have long narr ow arms allowing them to move very quickly. They can regenerate missing body parts that break of ve ry readily. oEchinoidea © Sea urchins and sand dollars have a rigid endoskeleton called a test. The y have barbs on their long spines, and some have venom. oHolothuroidea © Armless cucumbers. They ha ve a soft body and modified tube feet surround their mouth. When threatened many sea cucumbers ejec t their internal organs through their anus, a defense mechanism called evisceration. They later reg enerate the lost parts. Didja Know? .....that a starfish's mouth is located on it's underside, or oral surface. The top of its body is called the aboral surface. 10 Question Review: 1.What size do echinoderms range in? 1cm to 1m in diameter. 2.Where do they live? All kinds of marine habitats. 3.W hat is their symmetry? They go from bilateral symmetry to radial symmetry. 4.What is pentaradial sym metry? A type of radial symmetry when the organism has five radii. 5.What is their support? They hav e an endoskeleton. 6.What's a water-vascular system? A network of water filled canals. 7.What are tu be feet? Small, moveable protrusions that aid in movement, feeding, respiration, and excretion. 8.Ho w do they reproduce? Sexually or asexually. 9.What are the five classes? Crinoidea, asteroidea, ophi uridea, echinoidea, and holothuroidea. 10.What systems do echinoderms lack that are very important i n most evolved animals? They have no circulatory, respiratory, or excretory systems. invertebrate s introduction animalia largest five kingdom system with over million species extreme variety shapes colors sizes made eukaryotic multicellular heterotrophic organisms that either aquatic terrestrial reproduce sexually asexually invertebrates type animal that have backbone they make about animal kin gdom some invertebrates earthworms butterflies jellyfish giant squid there kinds lower higher lower further behind evolution they very soft squishy more vulnerable predators higher further along evolu tion they tougher considered less vulnerable porifera general characteristics osponges hollow cylind ers that closed bottom have opening called osculum othe cylinder lined with special collar cells cho anocytes which beating their flagella pulls water into sponge through pores canals circulates throug h osculum osponges live sessile lifestyle when collar cells pump water into sponge also screen bacte ria unicellular algae protozoans bits organic matter engulf known filter feeding owhile circulating water wastes excreted into exits osculum ofor support some sponges have simple skeletons made protei n fibers called spongin others skeletons made tiny hard particles called spicules osponges reproduce asexually forming small buds break live seperatley sexually sending sperm pores another sponge evol utionary development porifera represents least evolutionarily advanced animals animal kingdom classe s ocalcarea spicules calcium carbonate ohexactinella spicules silicon dioxide odemospongiae spongin combination spongin silicon dioxide osclerospongiae plus silicon dioxide calcium carbonate didja kno w sponges come every color rainbow also come many varied forms such mossy mats cacti blobs fungus ta ll tubes questions review what opening what another name collar cells choanocytes sponges sessile wh at does this mean means attach themselves firmly surfaces move main diet bacteria unicellular algae protozoans bits organic matter method eating filter feeding skeletons porifera known spicule means r eproduction sexually asexually regeneration four classes calcarea hexactinella demospongiae sclerosp ongiae kind invertebrate lower higher because further behind evolution pumping rapidly whip their fl agella every which direction cnidaria general characteristics ocnidarians either polyp vase shaped m edusa bell shaped polyp specialized sessile life medusa swimming othey consist cell layers endoderm ectoderm between them jelly like substance mesoglea feed their tentacles capture prey parylize with coiled stingers nematocysts located cnidocytes stinging which characterize cnidarians oafter capturi ng prey drawn mouth gastrovascular cavity hollow enzymes break food specialized lining cavity absorb owastes undigested foods expelled through mouth ocnidarians radial symmetry evolutionary developmen t cnidarians date back million years split from when developed layered skin layers classes ohydrozoa this includes polyps medusae species alternate between oscyphozoa true jellyfishes spending most li fe cycle medusae oanthozoa live only polyps include anemones corals didja know different forms cnida rians medusa polyp resulted from different arrangement same body parts question review difference be tween vase shaped bell specialized life swimming three layers cnidarian ectoderm mesoglea endoderm c oiled stingers tentacles nematocysts hollow cnidarian known gastrovascular cavity kind symmetry radi al symmetry stinging characterize cnidocytes anthozoa entire polyps name three cnidaria hydrozoa scy phozoa anthozoa wastes undigested foods send them back mouth platyhelminthes general characteristics othey bilaterally symmetrical othey lack respiratory circulatory systems flat omostly aquatic othei r soft bodies cause them unprotected from predators dehydration oflatworms hermaphroditic reproduce when planarians simultaneously fertalize eachother regeneration capable fertalizing eggs usually don t evolutionary development flatworms first animals bilateral cephalization three tissue oturbellaria marine environments hermaphroditic free living otrematoda parasitic flukes oval long sucker mouths ocestoda parasitic tapeworms hooks suckers grow long didja know planarians feed extending tube phary nx sucking food kind like straw question review planarian bilaterally symmetrical systems planarians lack circulatory respiratory system body type planarian flat soft very squishy hermaphroditic ferta lize themselves usually dont simultaneously fertalize eachother absorbing eachother sperm regenerati on turbellaria trematoda cestoda only free living class turbellaria pharynx tube some animals extend s functions eating nematoda round slender bodies taper each omost covered protective flexible cuticl e range less than length otheir digestive tract openings anterior posterior anus oparasitic both pla nts most free living othe male smaller than female omost varieties roundworms aren bilaterally symme trical roundworms first different sexes developed adaptations parasitism osecernentea somewhat porou s oval cleft like oadenophorea characterized reduced absent caudal papillae excretory system lacking latoral canals these organisms usually infective final host most common roundworms ascaris ancylost oma necator trichinella question type body long slender tapered each range size range length many op enings digestive tract placement anus anterior anus posterior lifestyle nematodes freeliving parstit ic both plants male larger than female female larger male true aren sure true first sexes nematodes nematodes secernentea adenophorea rotifera orotifera transparent swimming microscopic marine fresh e nvironments nanometers much larger males orotifers crown cilia around while feeding cilia sweep food this moves pharynx mastax muscular organ chops feed unicellular algae bacteria protozoa skeleton ma intain shape hydrostatic pressure within pseudocoelum crown cilia surrounds rotifer adaptation odigo nonta paired ovaries there orders bdelloidea selsonidea omonogononta there forms females posses ovar y males only present several days year orders collothecacea flosculariacea ploimidia under microscop e while rotifer beats apears rotating wheels environment rotifera marine freshwater size rotifera an ywhere nanometers females much males structure adaptation crown around explain rotifer process sweep then passes mastax protozoa maintain shape since skeleton maintain shape hydrostatic pressure withi n pseudocoelum digononta monogononta orders digononta bdelloidea seisonidea monogononta collothecace a flosculariacea plamida annelida coelums otheir divided many segments metamerism omost annelids ext ernal bristles setae function movement osome fleshy appendages parapodia oterrestrial aquatic enviro nments anterior segment earthworms reflect cephalization thats adaptation burrowing also gizzards ad apted burrowing grinds soil ooligochaeta over segments metameric units move earthworm anchors poster ior setae elongates forward then anchoring setae pulling forward burrow soild organic matter same ti me passes esophogus crop then gizzard closed circulatory oxygen carbon diffused directly across skin requires moist skin though capable fertalizing opolychaeta habitats predators somw burrow sediment other pump scour floor tentacles onirudinea theyre leeches suckers each calm bodies freshwater leech es often used doctors reattachment part proper blood flow will take place will allow operation succe ssful coelum annelids coelums annelid divided segments metamerism external bristles function functio n movement parapodia fleshy appendages annelid terrestrial oligochaeta polychaeta nirudinea class ea rthworm fall oligochaeta make class nirudinea leeches gizzard structure adapted burrowing grinds soi l mollusca very mollusks shell protects conceals osome sedentary filter feeders other predatory osqu ids octopuses move propulsion oall mollusks coelum main parts muscular foot head visceral mass organ systems circulations respiration digestions excretion nerve impulse conduction reproduction ousuall y more shells mollusks adapted shell because protected shell posed problem because reduced area avai lable exchange problem fixed adaption evolved gills opolyplacophora chitons seashore mostly rocks sh ells divided four seperate overlapping plates ogastropoda single shells torsion visceral mass twists degrees relation head twisting brings mantle front allows draw head mantle endangered obivalvia val ves muscular foot foot acts anchor holds down sand ocephalopoda meaning large well developed predato ry existence strong suckers kill prey help radula sharp beak closed result torsion during larval sai l above though protective feeders others predatory feeders coelum main parts visceral mass squids oc topuses means movement propulsion bilateral organ respiratory digestive excretory nerve impulse cond uction reproduction four polyplacophora gastropoda bivalvia cephalopoda cephalopoda veins arteries c apillaries does bivalvia uses anchor held sand creatures arthropoda oall jointed appendages extensio ns includes legs antennae osegmented pair segment though changed species exoskeletons ventral nervou s open sensory receptors order arthropods grow must periodically shed form exoskeleton process molti ng evolved more million years arthropods evolved common ancestor arthropods shows having less time g oes otrilobita extinct organisms trilobites ocrustacea shrimp lobsters crabs barnacles ciadocerans o stracods crayfish fleas copepods ochelicerata spiders scorpions ticks mites spiders horseshoe crabs ouniramia group land includes centipedes millipedes insects exoskeleton mostly protein tough carbohy drate chitin waxy outer layer repels prevents desiccation hard middle layer provides important prote ction flexible inner layer allows freely extensions legs antennae protection exoskeleton ventral ner vous open sensory receptors must order grow must molt molting process shed form about evolve years a rthropoda trilobita crustacea chelicerata uniramia extinct trilobita group land uniramia uniramia ce ntipedes millipedes insects insecta obody thorax abdomen othe pair antennae thorax pairs jointed leg s pairs wings abdomen eleven wings attached exoskeletons jointed segmented othere categories insects apart structural variations physiological variations behavioral variations open breath lungs gills tiny openings abdomen thorax spiracles adaptations such those other allowed successful reproductive organs both grasshoppers located insect pair pairs eleven categories apart structural physiological behavioral breath spiracles spiracles tiny breath well segmented insect wings attached attached echi nodermata inhabit kinds diameter often brilliant coloring undergo metamorphosis larva bottom dwellin g adult radial five radii pentaradial endoskeleton vascular network filled canals tube feet respirat ion excretion excretory ohave nervous brain othere sexes echinoderms existed over ancestors scientis ts believe echinoderms used ocrinoidea stalk rock bottom five extending arms branch arms much arms o asteroidea these stars starfish oysters clams used humans oophiuridea these basket brittle stars nar row allowing quickly regenerate missing break readily oechinoidea urchins sand dollars rigid endoske leton test barbs spines venom oholothuroidea armless cucumbers modified feet surround threatened cuc umbers eject internal organs defense mechanism evisceration later regenerate lost starfish located u nderside oral surface aboral surface size echinoderms diameter where kinds habitats bilateral pentar adial organism radii support endoskeleton vascular network filled feet small moveable protrusions re spiration excretion crinoidea asteroidea ophiuridea echinoidea holothuroidea lack importantEssay, es says, termpaper, term paper, termpapers, term papers, book reports, study, college, thesis, desserta 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