POINT > List characteristics of all worms POINT > Identify 3 phyla of worms POINT > Describe flatworms POINT > Describe roundworms POINT > Describe segmented worms POINT > Explain importance of worms in soil

POINT > List characteristics of all worms Worms are invertebrates Worms have soft bodies, usually tubular Bilateral symmetry: head and tail ends Organ-level of organization: simple brain, digestive organs, some have many hearts Reproduce both sexually and asexually, some hermaphrodites

POINT > Identify 3 phyla of worms Phylum 1. Platyhelminthes: the flatworms

POINT > Identify 3 phyla of worms Phylum 2. Nematoda: the roundworms

POINT > Identify 3 phyla of worms Phylum 3. Annelida: the segmented worms

CHECK: What are the three phyla of worms? What kind of symmetry do worms have?

POINT > Describe flatworms (Platyhelminthes) Flatworms are flat and soft Some are “free-living”, others are parasites Ex. Planarians are free-living flatworms Glide around and feed on dead and decaying things or hunt smaller organisms Have eyespots (sense light)

POINT > Describe flatworms (Platyhelminthes) Flatworms are flat and soft Some are “free-living”, others are parasites Ex. Tapeworms are parasitic flatworms Live in a host (including human) attached to intestinal wall Absorb the host’s nutrients directly through skin Pieces of its body fall off and are released in feces

CHECK: What flatworm is free-living? What flatworm is a parasite?

POINT > Describe roundworms (Nematoda) Roundworms have round bodies with pointier ends Ex. C. elegans is a free-living roundworm C. elegans is widely used in genetic research. We have learned what every cell in the C. elegans body does Roundworms live almost anywhere that is wet/moist Huge numbers! 1,000,000 per m 2 80% of all animals on earth! So they are very important in ecosystems.

POINT > Describe roundworms Roundworms have round bodies with pointier ends Ex. Ascaris is a human intestinal parasite (~ 700,000,000 people each year) Attaches to intestine and absorbs food through its skin

POINT > Describe segmented worms (Annelida) Annelids are worms with many repeating segments Annelids can be free living or parasitic Have a nerve cord and brain

POINT > Describe segmented worms (Annelida) Annelids have bodies with many repeating segments Ex. Earthworms and sandworms are free-living annelids

POINT > Describe segmented worms (Annelida) Annelids have bodies with many repeating segments Ex. Leeches are parasitic annelids

CHECK: What annelid is a human parasite? What roundworm is a human parasite? What roundworm is used in scientific research?

POINT > Explain importance of worms in soil Earthworms are very beneficial for gardens and plant growth As they tunnel they make the soil looser, which allows air and water to get into the soil They make the soil more fertile as it passes through their bodies

Review Level of Organization: Sponges – cellular Cnidarians – tissue Worms – organ/organ systems

VIDEOS (EW) (TW) (frog eating worm) (tapeworm life cycle)

Homework: Read pages S. A. page 320 #1-2 GRAS Pages