Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Phylum Annelida: Segmented Worms Chapter 27~~~ IN 121 A. General Characteristics Phylum: Annelida 1. Annelid: means“tiny rings” 2. Class: Oligochaeta 3. Examples: bristleworms, earthworms, leeches. 4. Bilateral animals w/ 2 body openings (mouth and anus). 5. Segmented Body 6. Live soil or freshwater 7. Nocturnal burrowing worm 8. Feeds on dirt filtering out organic matter 9. Beneficial to the soil: aeration (opening up soil to allow air to circulate better), fertilization 10. Respiration: oxygen diffuses across moist skin 11. Sexual Reproduction- hermaphrodites (Earthworms & Leeches) 12. Closed circulatory system: blood contained within vessels, 13. Well Developed Nervous System B. Earthworm Parts 1. Crop: temporary storage sac after mouth 2. Gizzard: sac w/muscular walls to grind soil 3. Intestine: long intestine stretches length of body to aid in digestion of soil 4. Ganglion: brain-like organ 5. Aortic Arches: Heart of worm; really 5 enlarged blood vessels. B. Earthworm Parts 6. Anus: wastes are removed 7. setae: bristles used for movement located on ventral side 8. Clittelum: enlarged reproductive segment, secretes mucus which helps hold worms together during reproduction Pathway of Digestion in an Earthworm 1. Prostonium (lip) 2. Mouth 3. Pharynx (the throat) 4. Esophagus 5. Crop 6. Gizzard 7. Intestine 8. Anus C. Leeches: 1. Class: Hirudinea 2. Parasitic segmented worm 3. Most live in fresh water 4. Have no bristles for movement, move w/muscular contractions 5. Suckers at each end of body 6. Medical Uses a. Anesthetic b. Increase circulation c. Secretions act as anticoagulants during feedings d. Reattachment of digits e. Reduce swelling f. Cosmetic surgery Segmented Worm Quiz 1. The term “annelid” means ___. a. Round worm b. flat worm 2. Annelids have ___symmetry and ___ body openings. a. Radial, 1 c. bilateral, 1 b. radial, 2 d. bilateral, 2 3. True/False: Earthworms have 5 true hearts. 4. To keep you from feeling it, the leech secretes an ___ when it bites into you to feed. a. Anesthetic b. toxin c. anticoagulant 5. True/False: Leeches serve a useful purpose to man. Section 27-3 Compare/Contrast Table Comparing Flatworms, Roundworms, and Annelids CHARACTERISTIC FLATWORMS ROUNDWORMS ANNELIDS Shape Flattened Cylindrical with tapering ends Cylindrical with tapering ends Segmentation No No Yes Body cavity Acoelomate Pseudocoelomate Coelomate Digestion and excretion Gastrovascular cavity with one opening only; flame cells remove metabolic wastes Tube-within-a-tube digestive tract; opening at each end; metabolic wastes excreted through body wall Tube-within-a-tube digestive tract; opening at each end; nephridia remove metabolic wastes Respiration Through skin; no respiratory organs Through skin; no respiratory organs Through skin; aquatic annelids breathe through gills Compare/Contrast Table continued Section 27-3 Comparing Flatworms, Roundworms, and Annelids CHARACTERISTIC FLATWORMS ROUNDWORMS ANNELIDS Circulation No heart, blood vessels, or blood No heart, blood vessels, or blood Blood circulated through blood vessels in closed circulatory system Response Simple brain; nerve cords run length of body; eyespot and other specialized cells that detect stimuli Several ganglia in head region; nerve cords run length of body; several types of sense organs Well-developed nervous system with brain and several nerve cords; many sense organs Movement Gliding, twisting, and turning Thrashing Forward peristaltic movement Reproduction Sexual (hermaphrodites); asexual (fission) Sexual (primary males and females) Sexual (some are hermaphrodites; some have separate sexes)