BIOL108 Lecture Notes - Lecture 23: Nematode, Apolysis, Moulting

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Lien Luong

Document Summary

Biol 108 - lecture #23 - ecdysozoa and nematodes. Ecdysis: molting the cuticle in order to grow: the cuticle prevents the organism from growing even bigger. Cuticle: non-living outer layer of skin: the cuticle is frequently sclerotized (hardens) Between the sclerotized layer and the cuticle, there is an unsclerotized cuticle in between. This layer is flexible and allows for movement. The cuticle: cuticle (cid:1372) 3 layers of cuticle (cid:1372) epidermis. Epidermis: living cells that secrete substances to the cuticle. Very fine ducts fun from epidermis to the top of the cuticle for the substances to travel in. Overview of molting process: moulting: starts loonnnng before there is any external evidence of skin shedding. Inactive moulting fluid is then secreted by the epidermis. Thin protective layer deposited between fluid and protective layer. New undifferentiated layer of cuticle deposied beneath protective layer. New cuticle is wrinkled but has a greater surface area than old cuticle.