BIOL108 Lecture Notes - Lecture 24: Protura, Pupa, Foregut

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

Document Summary

Arthropod characteristics: cephalization: development of head. Nervous tissue became concentrated towards the head during evolution. Head region is composed of several segments specialized for feeding and sensing: open circulatory system, jointed appendages. Eg. tail of scorpion is for defense. Appendages are something that you add onto the main body: segmented body. Due to hox genes: sclerotized cuticle. Provides support (hence life on land - because of gravity) and a rigid surface for muscles attachment: tagmatization. Segmented body and jointed appendages arranged into functional units with specialized. The head and the thorax is often merged as the cephalothorax. Crustaceans: crabs, lobsters, etc: 40 000-50 000 extant species, mostly marine, but some freshwater and some terrestrial species, huge ranges of organism sizes, morphology (can vary) Compound eyes (which are often on stalks) and has multiple lens on each eye. Shield that covers the dorsal and lateral sides. 2 or more appendages that helps to guide the food.