BIOL108 Lecture Notes - Lecture 24: Arthropod, Trilobite, Myriapoda

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

Document Summary

Nervous tissue becomes concentrated toward head during course of evolution head region composed of several segments specialized for feeding and sensing. Jointed appendages arthros = joint, pod = foot specialized functions (walking, feeding, sensory, reproduction, defense) Segmented body changes to regulation of hox genes - played a role in segment diversification. Sclerotized cuticle made of chitin acts as an exoskeleton must moult to grow provides support (life on land!) and a rigid surface for muscles attachment. Segmented body & jointed appendages arranged into functional units w/ specialized functions (division of labour) 40-50 thousand extant species mostly marine, but many freshwater and some terrestrial species morphology. 2 pairs of antennae compound eyes (often on stalks) Cephalothorax usually covered by a carapace shield that covers dorsal and lateral sides carapace sometimes also covers abdomen. 2 or more pairs of appendages that help guide food. Abdominal limbs are used for many things swimming, filter feeding, holding eggs.