Invertebrates

Introduction Invertebrates lack a spinal column Account for 98% of known animal species Classification of these organisms is extremely complex and constantly changing

Vocab terms Spicules –needle-like structures in Porifera – part of the skeleton in nematoda – reproductive structures Nematocysts –stinging cell found in Cnidaria Gastrovascular cavity – body cavity in Cnidaria that digests food and transports nutrients through body. Has one opening out of the animal that food comes in and out of.

Vocab terms Acoelomate – organism lacking a colon Complete digestive tract – digestive system has two openings Pseudocoelom – a fluid filled body cavity that surrounds the internal organs Pseudocoelomate – an organism with a three-layered body and a pseudocoelom Setae – stiff, hair-like structure Close circulatory system – blood flows through blood vessels (like mammals) Open circulatory system – Body cavity is filled with blood, no distinct blood vessels

Vocab terms Hydrostatic Skeleton – a skeleton composed of a fluid filled body cavity Mantle – the dorsal body wall of molluscs that cover the digestive and reproductive organs and aids in movement. Pedipalps – Arthropoda subphylum Chelicerata, the second pair of appendages of the prosoma in the subphylum Chelicerata. Chelicerae – the the mouthparts Arthropoda subphylum Chelicerata

Day 1 Dissections Ascaris lumbricoides (giant roundworm) Grasshopper Due Next time: No assignments due Quiz over O through S terms

Day 2 Dissections Grasshopper Squid Due Next time: Invertebrate Questions STUDY FOR MIDTERM!