1. S.M.Joshi College, Hadapsar.
Worms
Tamboli A.Z.
Department of Zoology
S.M.Joshi College, Hadapsar.
F.Y .B.Sc.

2. DO NOW Write down your homework Take out your foldable
On the back of your foldable answer this question
What made scientists put worms in a different category from cnidarians and sponges?

3. Worms What are the major classifications of worms?
Flatworms – Platyhelminthes
Roundworms – Nematoda
Segmented - Annelida
Name 5 characteristics of all worms. 
Invertebrates, Long narrow bodies without legs, bilateral symmetry, have tissues, organs, and body systems 
How does a worm with both male and female parts usually reproduce?
Mating – transfer of sperm 
How do worms reproduce asexually? 
Can sometimes grow individual worms from pieces

4. Worms Sense organs, mouth at anterior
Long, slender body allows rapid movement / control of direction
Three phyla
Flatworms - Platyhelminthes
Roundworms - Nematoda
Segmented worms - Annelida

5. Characteristics of all worms.
Inverts
Bilateral symmetry
Have a brain
Simplest organisms with a brain
Cells, Tissues, Organs, and Body Systems
Long narrow bodies without legs
Reproduce Sexually and Asexually

6. FAT WORMS - Platyhelminthes
What characteristics do all flatworms share?
Flat, soft as jelly 
What may parasitic flatworms do to their host?
Lives inside a host and takes food from it.
Give an example of a parasitic flatworm.
Tapeworm – absorbs food from the host’s digestive system 
Give an example of a free-living flatworm. 
Planarian – is free living because it can survive outside its host
How do planaria get food?
Scavengers – feeding on dead or decaying material. Glides onto its food and inserts a feeding tube. Digestive juices break down food outside of the body. Food is sucked up through this tube, and waste also exits this tube.

7. Phylum Platyhelminthes: Flatworms
planarian
Thin (few mm thick)
Bilaterally symmetrical
Single opening to pass food and waste
Pharynx extends out to suck in food
Free-living or parasitic
Regeneration

8. Class Turbellaria: Free-living flatworms
Marine / freshwater
Carnivores or
scavengers
Light sensitive
eyespots
Pharynx brings food into gastrovascular cavity
Planarian

9. Class Trematoda: Parasitic flatworms
“Flukes”
Infect internal organs of host
Some live on outside of host

10. Schistosomiasis --- Blood fluke
Affects 200 million people
Schistosoma egg in liver

11. Schistosomiasis larvae Intermediate host
Eggs clog blood vessels in liver, spleen, lungs, intestines
Intermediate host

12. Class Cestoda: Tapeworms
Parasitic; flat and long
Need no digestive system
scolex
proglottids

13. Taenia
Tapeworms can grow to several meters in length in the intestine

14. Tapeworm life cycle tapeworm attaches inside host intestine
zygotes
larval cysts

15. Roundworms - Nematoda
How are roundworms different from cnidarians or flatworms
They have a one-way digestive system that is tube like with a mouth and an anus. 
Describe the body of a roundworm.
Small, have a mouth and anus, many have transparent bodies, round

16. Phylum Nematoda: Roundworms
Free living or parasitic
Digestive tract has two openings

17. Disease- causing roundworms: Trichinella
Transmitted by consuming improperly cooked pork
Trichinosis
Disease caused by trichnella

18. Disease-causing Roundworms: Elephantiasis
Worm infects blood and lymph vessels
Transmitted by mosquitoes
Tropical parts of Asia
Swelling caused by blockage of lymph vessels

19. Disease-causing Roundworms: Ascaris
Parasitic roundworm
Affects humans, cats, dogs, horses, pigs, chickens
Cause severe malnutrition
Spread by eating food or water contaminated with Ascaris eggs
Intestine filled with Ascaris

20. Hook Worms Enter the body through the skin on the soles of the feet
Live in the blood and intestines

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

22. Pinworm (Enterobius)
0.5 inches long

23. Guinea Worms
Dracunculus medinensis

24. Guinea Worms

25. Segmented Worms - Annelida
Describe the body of a segmented worm.
Have a mouth and anus that are separated by segments 
Name 3 characteristics of all segmented worms.
All have a nerve cord, digestive tube, and a closed circulatory system. 
What is a closed circulatory system
Blood moves within a closed network of tubes called vessels.

26. Phylum Annelida: Segmented Worms
Body divided into segments by internal walls, “septa”
In many annelids, segments specialize for specific function:
Eyes
Antennae
Respiration
Example: earthworm

27. Earthworm Over 100 segments Closed circulatory system
All fluids contained within small tubes
Oxygen enters through skin
Gizzard – grinds dirt and soil
Setae – bristles that are located on the underside aid in movement
Mucus – slippery substance that helps the earthworm move

29. Aerating the soil

30. Examples to know:
*Phylum Platyhelminthes (flatworms)
Planarian, free living
Tapeworm, parasitic
Flukes: ex. Schistosoma, parasitic, causes Schistosomiasis
*Phylum Nematoda (roundworms)
Trichinella, parasitic, causes trichinosis
filarial worms, parasitic, causes Elephantiasis (filariasis)
Ascaris, parasitic
hookworms, parasitic
pinworms, parasitic
Guinea worms, parasitic
*Phylum Annelida (segmented worms)
earthworm, free living
Nereis, free living
leech

31. Closing – Crumble and Toss
Get a piece of paper
How does the structure of the segmented worm affect its function?
Planarian?

32. Words to know Scissors ( no scapel), forceps, dissecting pins
Anterior – Head end
Posterior – Butt End
Ventral – Stomach side (light color)
Dorsal – Back side ( Dark Blood Vessel)

33. What am I?