Three Phyla of Worms. Review the Animal Kingdom 4 Major Characteristics? Multicellular Eukaryotic...
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Transcript of Three Phyla of Worms. Review the Animal Kingdom 4 Major Characteristics? Multicellular Eukaryotic...
Three Phyla of Worms
Review the Animal Kingdom 4 Major Characteristics?
Multicellular
Eukaryotic
Heterotrophs
Cells lack cell walls
7 Essential Functions? Feeding
Respiration
Circulation
Excretion
Response
Movement
Reproduction
Brain Encased Skull
jawsBony Skeleton
Lungs
Amniotic Egg
Hard Shells
Fur & Milk Glands
Water flow
Collar Cell
Spicule
Pore cell
Pore
Epidermal cell
Archaeocyte
Osculum
Central cavity
Pores
The Anatomy of a Sponge
Ecology of Sponges
1. Ideal habitats for marine animals such as snails, sea stars, sea cucumbers, and shrimp
2. Mutually beneficial relationships with bacteria, algae and plant-like protists
Examples: hydra, coral, sea anemone
Examples: jellyfish, portuguese man of war
Cnidarians have two body forms
Polyp - stationary, vase-shaped
Medusa - swimming, cup-shaped
Ecology of Cnidarians A. Source of new drugs/chemicals sunscreen
855 B. Provide habitats for marine organisms C. Source of food for other organisms (like sea
turtles) D. Symbiotic relationships with other organisms
WORMSPhylum: Annelida
Phylum: Platyhelminthes
Phylum: Nematoda
What’s a Worm???
A long, thin invertebrate with BILATERAL symmetry, a nervous system, and cephalization
Simplest animal to have a true organs like a brain! Reproduction - Sexual (hermaphroditic – male and female
reproductive organs) and Asexual – Fission (breaking into pieces)
Many are parasites- (good/bad relationship) live on or in a
host
3 Distinct Phyla Platyhelminthes (flatworms) Nematoda (roundworms) Annelida (segmented worms)
http://animal.discovery.com/videos/monsters-inside-me-tapeworm-in-my-brain.html
http://animal.discovery.com/videos/monsters-inside-me-flesh-eating-hookworm.html
http://planetgreen.discovery.com/videos/g-word-red-wigglers.html
http://animal.discovery.com/videos/top-10-bloodsuckers-leech.html
Characteristics of Flatworms (Platyhelminthes)
A. Soft flattened worms with true tissues and internal organs.
B. Simplest animals to have bilateral symmetry and cephalization.
Flatworms carry out 7 essential functions1. Feeding – some carnivorous,
most parasitic; one opening into gut; pharynx sucks in food and releases waste
2. Respiration/ Circulation/ Excretion – No respiratory No circulatory system, system; Obtain nutrients and oxygen by diffusion directly into cells. Simple excretory system of specialized cells.
3. Response/Movement – ganglia= groups of nerves in head control nervous system (like a brain); “ladder” of nerves run over body; eyespot detects light; move by cilia and squirming using outer layer of muscle tissue
Diseases caused by parasitic flatworms
A. Flukes-Usually infect internal organs of host – Example: The blood fluke Schistosoma- causes tissue damage that could result in death
Section 27-1
Flukes mature and reproduce sexually in the blood vessels of human intestines. Embryos are released and passed out with feces.
Once in the water, embryos develop into swimming larvae that infect an intermediate host (snail).
After asexualreproduction, newlarvae are releasedfrom the snail into the water. They then infect humans, the primary host, by boring through their skin.
Primary host (human)
Intermdiate host(snail)
Humanintestine
Adultfluke
Embryo
Ciliatedlarva
Tailedlarva
Schistosome Life Cycle
Primary host
Secondary host
4. Inside the human host, the flukes produce eggs that clog blood vessels, causing swelling and damage to lungs, liver, spleen, and/or intestines
Diseases caused by parasitic flatworms
A. Flukes-Usually infect internal organs of host – Example: The blood fluke Schistosoma
B. Tapeworms – Long, flat, and have adaptations for life inside intestines of host
Parasitic FlatwormsParasitic Flatworms Head with a scolex -
suckers and hooks which attach to the host’s intestinal lining
Check Your Understanding What type of symmetry do all worms have?
Worms are the simplest animals to have ____________ and ______________.
How do flatworms obtain nutrients and oxygen?
Bilateral symmetry Cephalization
Bilateral
Diffusion
The Characteristics of Roundworms Phylum Nematoda
A. Body plan- First animals to have a one way digestive system with mouth and anus (tube within in a tube);
B. First animals to have a fluid filled body cavity called a pseudocoelom- “false body cavity”
Roundworms Carry Out 7 Essential Functions
1. Feeding- many are carnivores with grasping mouthparts, some herbivores, many are parasites
2. Respiration/Circulation/ Excretion- No Respiratory or Circulatory Systems; rely on diffusion. Simple excretory organs.
3. Response/movement -have ganglia (“brain”)and simple nervous system, have muscular system and move like snakes
Diseases caused by parasitic roundworms
A. Trichinella causes painful cysts in the muscle tissue of humans and other animals- transmitted by eating undercooked meat containing worm eggs
Diseases caused by parasitic roundworms
B. Filarial worms cause Elephantiasis- fluid buildup that causes abnormally large limbs – transmitted through the bite of insects like mosquitos
Diseases caused by parasitic roundworms
C. Ascarids cause malnutrition in humans, horses, cows, etc by filling the intestinal tract of its host and absorbing all nutrients
Diseases caused by parasitic roundworms
D. Hookworms attach to the lungs and intestines and suck blood – common in humans(1/4 of world population); larvae pierce the skin & burrow into the body. Can severely damage internal organs. Transmitted through humans’ and other animals’ waste. (Wear Shoes!)
Check Your Understanding What is different about the roundworm’s
digestive system as compared to the flatworm’s digestive system?
How are roundworm diseases transmitted?
What are ganglia?
A roundworm has a mouth and anus. A flatworm only has one opening
By eating undercooked meat, walking barefoot, insect bites
Nerve tissue that function as simple brains
Phylum Annelida
anus
mouth clitellum
Figure 1 – Body Structure
Phylum Annelida A. Body Plan- tube
within a tube, digestive system with mouth and anus; body divided into sections called septa that are specialized for different functions. First animals to have true circulatory system and coelom – body cavity.
Annelids carry out 7 essential functions?
1. Feeding- predators to filter feeders; use pharynx to get food, stored in crop, ground up in gizzard, absorbed in intestine.
Mouth pharynx esophagus (throat) crop (storage area) gizzard (grinds food) intestines (digestion) anus
One-way Digestive System
Annelids carry out 7 essential functions?
2. Circulation/ Respiration/ Excretion- closed circulatory system with vessels; breath through gills or through skin; have excretory organs called nephridia
Annelids carry out 7 essential functions?
2. Circulation/ Respiration/ Excretion- closed circulatory system with vessels; breath through gills or through skin; have excretory organs called nephridia
3. Response/Movement- have ganglia in each segment and in the head, nervous system; move by contracting and relaxing muscles
Section 27-3
Anus
Clitellum
Circular muscle
Longitudinalmuscle
Nephridia Ganglia Ringvessels
Reproductiveorgans
Ventralblood vessel
Ganglion
Brain
Mouth
Dorsalblood vessel
CropGizzardBody segments
Setae
The Anatomy of an Earthworm
Anus
Mouth
Brain
Aorticarches
Dorsal blood vessel
Crop (stores)
Gizzard(grinds)
Intestine
Clitellum
Ventral blood vessel
Ventral nerve cord
Esophagus
Pharynx(throat)Segments
Ecology of AnnelidsA. Aerate, mix, and fertilize the soil- have created
some of the most fertile soils on earth!
B. Tunnels provide passage ways for plant roots and water
C. Important in the diets of many other animals such as birds, toads and snakes; marine annelids important in the diets of fishes, crabs, and lobsters
Check Your Understanding Name one characteristic all three worm
phyla have in common
What type of circulatory system do segmented worms have?
Figure 2 – Reproductive Structures
Clitellum
Sperm Grooves
Male genital pores
setae
prostomium
Earthworm coccoons
mouth
brain
pharynx
Aortic arches
Seminal vesiclessepta
Dorsal blood vessel
crop
gizzard
Intestine
Seminal receptacles
ovaries
esophagus
Ventral nerve cordmetameres
Ventral blood vessel
nephridia
Review What are the three types of worms? How do worms such as a planarian “see”? What kind of worm includes leeches and
marine worms? What makes a segmented worm, such as an
earthworm, different from other worms in regards to their circulatory system?