bilateral symmetry
Body plan in which only a single, imaginary line can divide the body into two equal halves.
Radial symmetry
body grows out in several directions symmetrically; has several or many axes
Asymmetrical
no clear symmetry; no obvious axis
Acoelomate
an animal that lacks a coelom, or body cavity (no body cavities around or between organs)
pseucoelomate
body cavity completely surround each organ
Coelomate
body cavities occur between organs and the cavities are lined with tissue that suspend and protect the organs
hydrostatic skeleton
fluid (water usually) filled structure lined with muscles cells that contract and push against the fluid. This creates stiffness needed for structural support and movement of body parts.
Good examples: earthworms of phylum annelida and hydra and sea anemo
What structure do most of the crustaceans use to breathe?
Gills
Why is it necessary for arthropods to molt?
needs further molting to become the adult, they do this by shedding their exoskeleton and regrowing new ones.
Name the 3 major body sections of insects?
head
thorax
abdomen
What are the major body sections of Chelicerata (Arachnids)?
cephalothorax
abdomen
spicules
small, spike shaped particles of calcium carbonate or silicon dioxide that make up the skeleton of some sponges
Grantia
Class Scyphozoa
jellyfish
Class Anthozoa
corals and sea anemones
Class Hydrozoa
Class Hydrozoa
Hydra
Class Hydrozoa
Obelia
Class Hydrozoa
medusae
Class Turbellaria:
Planaria or Dugesia
Class Trematoda
flukes
Clonorchis
Class Cestoda
tapeworms
Class Oligochaeta
Lumbricus (earthworm)
Class Hirudinea
leeches
Class Polychaeta
marine worms
Class Gastropoda
snails and slugs
Class Bivalvia
clams
Class Cephalopoda
squid, octopus
Class Polyplacophora
chitons
Trichinella
vinegar eels
Class Crustacea
crayfish
Class Insecta
insects
Class Chilopoda
centipedes
Class Diplopoda
millipedes
Class Chelicerata
spiders and horseshoe crab