BIOL 111 Lecture Notes - Lecture 4: Schistosoma, Cable Television Headend, Digestion

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

Cnidarian reproduction through mitosis, a polyp may produce a medusa and release it. Evolutionary innovation: the development of a head flatworms develop a head with two auricles that house chemoreceptors and have two eyespots that contain photoreceptors (can detect light, but cannot form images) Flatworms (phylum platyhelminthes) there are about 25000 known flatworms usually live in moist terrestrial or aquatic environments. Move by cilia are in a group called lophotrochozoans: counter to ecdysozoans are free-living or parasitic can grow from 1 mm to 10 m are triploblastic. By this uneven illumination, flatworms can detect from which direction light/shadows are. Most flatworms are internal parasites parasitism is a symbiosis where the one organism (the parasite) benefits and one organism (the host) suffers. Mutualism is symbiosis where all participating organisms are benefiting a parasite must disperse offspring while host is still living parasitic flatworms can live in multiple hosts.