BIOL 312 Lecture Notes - Lecture 2: Advanced Photon Source, Hexapoda, Sea Louse

• School: University of Victoria
• Department: Biology
• Course: BIOL 312
• Professor: Steve Perlman

Document Summary

Major themes/features in arthropod evolution: rigid exosletelon, tagmosis: organization of body parts (regional specialization - tag(cid:373)ata(cid:895), fu(cid:374)(cid:272)tio(cid:374)al di(cid:448)ersifi(cid:272)atio(cid:374) of appe(cid:374)dages (cid:894)(cid:858)arthropod(cid:859) (cid:373)ea(cid:374)s joi(cid:374)ted feet) Insects (within) hexapods (within) arthropods all insects are arthropods; not all arthropods are insects. Six legs is(cid:374)(cid:859)t o(cid:374)ly a feature of i(cid:374)se(cid:272)ts there are hexapods (6 legs) which are not insects. Scorpions, spiders, ticks, mites, daddy long legs (arachnids) Insect (arthropod) exoskeleton highly flexible (stretching in honeypot ants repletes store food and regurgitate stores for other ants when necessary) Chitin: polysaaccahraide + other proteins for hardening: plates separated by flexible membrane (suit of armour), secreted by epidermis. Infolding of exoskeleton foregut, hindgut, sites from muscle attachment. Strong and rigid, lightwight protection against physical and chemical damage and predators/pathogens versatile muscle, limb attachment. Exoskeleton must be shed for growth to occur molting exposes animal to harm until hardened. Also, necessitates alternate mode of movement, gas exchange.