Good Morning!! 1.SURPRISE!!! You have a new seat! Find your new seat then finish your flap book that you worked on yesterday (You will have 10 minutes after the announcements to finish). 2.Place in basket when finished 3.For early finishers, start working on the sponges coloring worksheet beside the basket.

Kingdom: Animalia Phylum: Platyhelminthes (Flatworms) Chapter 25 Section 1

Structure and Function Approximately 20,000 species! Acoelomates Bilateral symmetry Definite head region and body organs Very thin Most parasitic Some free-living

Where do they live? Parasitic: Inside bodies of animals Free-living: Marine, freshwater, moist land habitats, underside of rocks in swiftly flowing streams

Feeding What do they eat? – Dead, or slow-moving organisms – Eat blood and other body tissues

Feeding How do they eat? – Pharynx- tubelike muscular organ that extends out of their mouths Releases enzymes that digest prey – Food sucked into digestive tract – Parasitic have feeding structures: – Hooks and suckers

Digestion Reduced digestive system: – Mouth, pharynx, gastrovascular cavity No digestive system in some Absorb nutrients from their hosts’ intestines One opening- wastes released through mouth

Respiration and Circulation No circulatory or respiratory organs Use diffusion: – distribute O 2 and nutrients in body – remove CO 2 and wastes

Excretion Excretory system- network of small tubes throughout the body Flame cells- allow flatworms to excrete waste materials from their bodies Substances exit through pores

Response to Stimuli Nervous system – 2 nerve cords with connecting nerve tissue Looks like the rungs of a ladder Swelling containing ganglia that send nerve signals (like a brain) Ganglion- nerve cell bodies that coordinates incoming and outgoing nerve signals

Reproduction Hermaphrodites- produce both eggs and sperm Sexual: – 2 different flatworms exchange sperm – eggs fertilized internally Marine: zygotes hatch from cocoons released into the water

Asexual: – Regeneration- regrow damaged or missing body parts

Movement Contract muscles in body wall Glide using cilia and mucus covering

Diversity 3 Classes: Free Living: – Turbellaria Parasitic: – Trematoda – Cestoda

Turbellarians Planaria 16% of all flatworms Free-living Most are marine, though some in fresh water & terrestrial

Trematodes Parasitic – Infect blood or body organs of their hosts Example: Shistosoma (parastic fluke) Cause the disease Shistosomiasis in humans

Life Cycle of Schistosoma 48 hours to find host & urine

Cestodes Parasitic Tapeworms Live inside intestines of host Proglottids- contain reproductive organs Animals can get tapeworms by eating plants or drinking water contaminated with tapeworm proglottids

Life Cycle of Beef Tapeworm

Life Cycle of Pork Tapeworm