Download INVERTEBRATES Introduction: Animalia is the largest of the

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
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