Worms Worms

Mr. DMr. D

DO NOWDO NOW

Write down your homeworkWrite down your homework Take out your foldableTake out your foldable On the back of your foldable On the back of your foldable

answer this questionanswer this question What made scientists put worms in a What made scientists put worms in a

different category from cnidarians different category from cnidarians and sponges?and sponges?

Worms Worms What are the major classifications of worms?What are the major classifications of worms?

Flatworms – PlatyhelminthesFlatworms – Platyhelminthes Roundworms – NematodaRoundworms – Nematoda

Segmented - AnnelidaSegmented - Annelida Name 5 characteristics of all worms. Name 5 characteristics of all worms. 

Invertebrates, Long narrow bodies without legs, bilateral Invertebrates, Long narrow bodies without legs, bilateral symmetry, have tissues, organs, and body systems symmetry, have tissues, organs, and body systems 

How does a worm with both male and female parts usually How does a worm with both male and female parts usually reproduce?reproduce? Mating – transfer of spermMating – transfer of sperm  

How do worms reproduce asexually? How do worms reproduce asexually?  Can sometimes grow individual worms from piecesCan sometimes grow individual worms from pieces

WormsWorms

Sense organs, mouth at Sense organs, mouth at anterioranterior

Long, slender body allows Long, slender body allows rapid movement / control rapid movement / control of directionof direction

Three phylaThree phyla Flatworms - PlatyhelminthesFlatworms - Platyhelminthes Roundworms - NematodaRoundworms - Nematoda Segmented worms - AnnelidaSegmented worms - Annelida

Characteristics of all Characteristics of all worms.worms.

InvertsInverts Bilateral symmetryBilateral symmetry

Have a brain Have a brain Simplest organisms with a brainSimplest organisms with a brain

Cells, Tissues, Organs, and Body Cells, Tissues, Organs, and Body SystemsSystems

Long narrow bodies without legsLong narrow bodies without legs Reproduce Sexually and AsexuallyReproduce Sexually and Asexually

FAT WORMS - FAT WORMS - PlatyhelminthesPlatyhelminthes

What characteristics do all flatworms share?What characteristics do all flatworms share? Flat, soft as jelly Flat, soft as jelly 

What may parasitic flatworms do to their host?What may parasitic flatworms do to their host? Lives inside a host and takes food from it.Lives inside a host and takes food from it.

Give an example of a parasitic flatworm.Give an example of a parasitic flatworm. Tapeworm – absorbs food from the host’s digestive systemTapeworm – absorbs food from the host’s digestive system  

Give an example of a free-living flatworm. Give an example of a free-living flatworm.  Planarian – is free living because it can survive outside its hostPlanarian – is free living because it can survive outside its host

How do planaria get food?How do planaria get food? Scavengers – feeding on dead or decaying material. Glides onto Scavengers – feeding on dead or decaying material. Glides onto

its food and inserts a feeding tube. Digestive juices break down its food and inserts a feeding tube. Digestive juices break down food outside of the body. Food is sucked up through this tube, and food outside of the body. Food is sucked up through this tube, and waste also exits this tube.waste also exits this tube.

Phylum Phylum PlatyhelminthesPlatyhelminthes: : FlatwormsFlatworms

Thin (few mm thick)Thin (few mm thick) Bilaterally symmetricalBilaterally symmetrical Single openingSingle opening to pass food and to pass food and

wastewaste Pharynx extends out to suck in foodPharynx extends out to suck in food Free-living or parasiticFree-living or parasitic RegenerationRegeneration

planarian

Class Turbellaria: Free-Class Turbellaria: Free-living flatwormsliving flatworms

Marine / freshwater

Carnivores orscavengers

Light sensitive eyespots

Pharynx brings food into gastrovascular cavity

Planarian

Class Trematoda: Class Trematoda: Parasitic flatwormsParasitic flatworms

““Flukes”Flukes” Infect internal organs of hostInfect internal organs of host Some live on outside of hostSome live on outside of host

Schistosomiasis ---Schistosomiasis ---Blood flukeBlood fluke

Affects 200 million peopleAffects 200 million people

Schistosoma egg in liver

Intermediate host

larvae

Eggs clog blood vessels in liver, spleen, lungs, intestines

Schistosomiasis

Class Cestoda: TapewormsClass Cestoda: Tapeworms Parasitic; flat and longParasitic; flat and long Need no digestive system Need no digestive system

scolexproglottids

Tapeworms can grow to several meters in length in the intestineTapeworms can grow to several meters in length in the intestine

Taenia

Tapeworm life cycle

zygoteslarval cysts

tapeworm attaches inside host intestine

Roundworms - NematodaRoundworms - Nematoda

How are roundworms different from How are roundworms different from cnidarians or flatwormscnidarians or flatworms They have a one-way digestive They have a one-way digestive

system that is tube like with a mouth system that is tube like with a mouth and an anus. and an anus. 

Describe the body of a roundworm.Describe the body of a roundworm. Small, have a mouth and anus, many Small, have a mouth and anus, many

have transparent bodies, roundhave transparent bodies, round

Phylum Nematoda: Phylum Nematoda: RoundwormsRoundworms

Free living or parasiticFree living or parasitic Digestive tract has Digestive tract has two openingstwo openings

Disease-Disease-causing causing roundworms: roundworms: TrichinellaTrichinella

Transmitted Transmitted by by consuming consuming improperly improperly cooked porkcooked pork

TrichinosisTrichinosis Disease Disease

caused by caused by trichnellatrichnella

Disease-causing Disease-causing Roundworms:Roundworms:ElephantiasisElephantiasis

Worm Worm infects infects blood and blood and lymph lymph vesselsvessels

Transmitted Transmitted by by mosquitoesmosquitoes

Tropical Tropical parts of Asiaparts of Asia Swelling caused by blockage of lymph vessels

Disease-Disease-causing causing Roundworms:Roundworms:AscarisAscaris

Parasitic roundworm Parasitic roundworm Affects humans, cats, dogs, horses, Affects humans, cats, dogs, horses,

pigs, chickenspigs, chickens Cause severe malnutritionCause severe malnutrition Spread by eating food or water Spread by eating food or water

contaminated with contaminated with AscarisAscaris eggs eggs

Intestine filled with Ascaris

Hook WormsHook Worms

Enter the body through the skin on Enter the body through the skin on the soles of the feetthe soles of the feet

Live in the blood and intestinesLive in the blood and intestines

HookwormsHookworms

This patient presented with a hookworm infection involving the toes of the right foot, which is also known as “ground itch”. Usually the first sign of infection is itching, and a rash at the site where skin touched contaminated soil or sand, which occurs when the larvae penetrate the skin, followed by anemia, abdominal pain, diarrhea, loss of appetite, and weight loss..

Hookworms penetrate the bottoms of bare feet. Do not go barefoot.

Necator

Pinworm Pinworm (Enterobius)(Enterobius)

0.5 inches long

Guinea WormsGuinea Worms

Dracunculus medinensis

Guinea WormsGuinea Worms

Segmented Worms - Segmented Worms - AnnelidaAnnelida

Describe the body of a segmented worm.Describe the body of a segmented worm. Have a mouth and anus that are separated Have a mouth and anus that are separated

by segments by segments  Name 3 characteristics of all segmented Name 3 characteristics of all segmented

worms.worms. All have a nerve cord, digestive tube, and a All have a nerve cord, digestive tube, and a

closed circulatory system. closed circulatory system.  What is a closed circulatory systemWhat is a closed circulatory system

Blood moves within a closed network of Blood moves within a closed network of tubes called vessels.tubes called vessels.

Phylum Annelida: Phylum Annelida: Segmented WormsSegmented Worms

Body divided into segments by internal Body divided into segments by internal walls, “septa”walls, “septa”

In many annelids, segments specialize In many annelids, segments specialize for specific function:for specific function: EyesEyes AntennaeAntennae RespirationRespiration

Example: earthwormExample: earthworm

EarthwormEarthworm

Over 100 segmentsOver 100 segments Closed circulatory systemClosed circulatory system

All fluids contained within small tubesAll fluids contained within small tubes Oxygen enters through skinOxygen enters through skin Gizzard – grinds dirt and soilGizzard – grinds dirt and soil Setae – bristles that are located on the Setae – bristles that are located on the

underside aid in movementunderside aid in movement Mucus – slippery substance that helps the Mucus – slippery substance that helps the

earthworm moveearthworm move

Aerating the soilAerating the soil

Examples to know:Examples to know: *Phylum Platyhelminthes (flatworms)*Phylum Platyhelminthes (flatworms)

Planarian, free living Planarian, free living Tapeworm, parasitic Tapeworm, parasitic

Flukes: ex. Flukes: ex. SchistosomaSchistosoma, parasitic, causes Schistosomiasis, parasitic, causes Schistosomiasis *Phylum Nematoda (roundworms)*Phylum Nematoda (roundworms)

TrichinellaTrichinella, parasitic, causes trichinosis, parasitic, causes trichinosis filarial worms, parasitic, causes Elephantiasis (filariasis)filarial worms, parasitic, causes Elephantiasis (filariasis)

Ascaris, Ascaris, parasiticparasitic hookworms, parasitichookworms, parasitic pinworms, parasiticpinworms, parasitic

Guinea worms, parasiticGuinea worms, parasitic *Phylum Annelida (segmented worms)*Phylum Annelida (segmented worms)

earthworm, free livingearthworm, free living Nereis, Nereis, free livingfree living leechleech

Closing – Crumble and Closing – Crumble and TossToss

Get a piece of paperGet a piece of paper How does the structure of the How does the structure of the

segmented worm affect its segmented worm affect its function?function?

Planarian?Planarian?

Words to know Words to know

Scissors ( no scapel), forceps, Scissors ( no scapel), forceps, dissecting pinsdissecting pins

Anterior – Head endAnterior – Head end Posterior – Butt EndPosterior – Butt End Ventral – Stomach side (light color)Ventral – Stomach side (light color) Dorsal – Back side ( Dark Blood Dorsal – Back side ( Dark Blood

Vessel)Vessel)

Flatworm Lab 3/8/2011Flatworm Lab 3/8/2011

Please pick up a worm lab and Please pick up a worm lab and read itread it

What am I?What am I?

Do Now 3/15/2011 TEST 9Do Now 3/15/2011 TEST 9

Pick up and Answer Sheet and packet Pick up and Answer Sheet and packet on the Chairon the Chair

After the TestAfter the Test Kids SurveyKids Survey Complete the Packet (on chair) Complete the Packet (on chair) Packet Due ThursdayPacket Due Thursday Remember to Get Frost Valley Activity Remember to Get Frost Valley Activity

Sheets in tomorrowSheets in tomorrow