Presentation on theme: "Worms Flatworms, Roundworms, and Segmented Worms Science7."— Presentation transcript:
1WormsFlatworms, Roundworms, and Segmented WormsScience7
2Characteristics of Worms All worms share the following characteristics:InvertebratesLong narrow bodies without legsTissues, organs, and organ systems (with brain)Bilateral Symmetry (head and tail ends)Reproduction: Sexual and Asexual3 Cell LayersEctodermMesodermEndoderm
33 Major Phyla of Worms There are 3 major phyla of worms: Platyhelminthes = FlatwormsNematoda = RoundwormsAnnelida = Segmented Worms
4Flatworms From 2 Greek words: Simplest of all worms Platy means “flat” Helminthe means “worm”Simplest of all wormsFlattened bodiesMost are parasites and get food from host
5Flatworms: 3 Types There are many kinds of flatworms: Planarians TapewormsFlukes
6Flatworms: Tapeworms Tapeworms Lives in the intestines of animals (including humans!)Uses hooks and suckers on its head to dig into the lining of an organism’s digestive tractConsidered ParasiticBlocks the host’s intestinesSteals valuable food and waterCan grow meters in length
8Flatworms: Planarians ScavengersA feeding tube releases digestive juices to break down food.THINK! – What type of digestion is this?Odor cells are found on the headTHINK! – What do the odor cells help with?Planarians have 2 photosynthetic eyespotsTHINK! – What do the eyespots detect?
9Flatworms: Flukes Flukes Usually live in the human liver Shape: Oval and flatSize: 2mm -15 cm
10Activity: Draw A Flatworm Draw, color, and label the diagram of this flatworm in your guided notes.MouthDigestive TractMuscular Tube for FeedingNerve Tissue
11Roundworms General Characteristics: Cylindrical bodies Contains a digestive systemFood enters at a mouthWaste exits through the anus
12Roundworms: Trichinella Lives in muscular tissue of pigsThese worms reproduce in the intestine of the hostFemale worms release hundreds of immature worms carried in the bloodstreamThese immature worms burrow in the surrounding tissue causing pain to the host
13Roundworms: Hookworms Enter the body by burrowing through the soles of feetEventually ends up in the intestines where they live off of blood
14Roundworms: Pinworms Pinworms Small white parasitic worms found in the feces of babiesBabies sometimes ingest microscopic eggs from the soil
15Activity: Draw A Roundworm Draw, label, and color this diagram of a roundworm in your guided notes. Compare it to a cnidarian which we just learned about.
16Segmented Worms Characteristics Annelida is Latin for “Little Rings” Body is made of many segmentsAn earthworm has more than 100 segments!Organs are found within the segments
17Segmented Worms: Closed Circulatory System Blood moves within a confined set of blood vesselsFive hearts are located in segments 5-13
18Segemented Worms: Earthworms How they liveThey tunnel for a livingThey are scavengers eating dead plant and animal remainsThey crawl by using stiff bristles to pull themselves along
19Segmented Worms: Earthworms Earthworms and SoilEarthworms make soil more fertileTheir tunnels help loosen the soil and allow air, water, and plant roots to move through it.
20Activity: Draw a Segmented Worm Draw, color, and label this diagram of a segmented worm in your guided notes.