| A | B |
|---|
| filter feeding | the process of obtaining nourishment by filter it out of surrounding water |
| Porifera | cell level; asymmetrical; acoelomates;sessile; examples include sponges |
| osculum | water and waste are expelled through this opening in a sponge |
| collar cells | a specialized cell that has a single flagellum surrounded by a collar; the flagella creates a water current to draw water through the pores of the sponge and the collar traps the food |
| spicules | The "skeleton" of a sponge; made of silica or calcium carbonate |
| radial symmetry | the arrangement of body parts that splits the body into mirror-image halves using many length-wise planes |
| cnidaria | tissue level; have ectoderm and endoderm; radial symmetry; acoelomates;some sessile, some mobile; examples include Hydra, jellyfish, coral |
| medusa | bell-shaped form of cnidarian; mouth on the lower surface; generally mobile |
| polyp | tobe-like form of cnidarian; mouth on upper surface; mostly sessile |
| nematocyst | the thread-like stinging structure in cnidarians; when discharged, pierce prey, they inject a toxin that paralyze the prey |
| budding | asexual reproduction in polyps |
| Platyhelminthes | incomplete system level; have ectoderm, mesoderm and endoderm; bilateal symmetry; pseudocoelomates; mobile; examples include flatworms like Planaria, flukes, and tapeworm |
| scolex | head of a tapeworm which contains hooks or suckers |
| proglottid | the body sections of tapeworm which contain the male and female reproductive organs |
| Nematoda | complete system level; have ectoderm, mesoderm and endoderm; bilateral symmetry; pseudocoelomates; mobile; examples include roundworms, hookworms, pinworms |
| pore cell | cells that have openings that bring water carrying food and oxygen into the sponge's body. |
| Invertebrates | animals without a backbone |
| bilateral symmetry | the arrangement of body parts that splits the body into mirror-image halves using only one length-wise planes |
| asymmetry | having no arrangement of body parts that splits the body into mirror-image halves using any length-wise planes |
| ectoderm | the outer cell tissue layer, which becomes the epidermis |
| mesoderm | the outer cell tissue layer, which becomes the skeleton, muscles, and reproductive and cirulatory organs |
| endoderm | the inner cell tissue layer, which becomes the lining of the digestive cavity |
| coelom | a fluid-filled body cavity completely surrounded by mesoderm |
| pseudocoelom | a fluid-filled body cavity that is not entirely surrounded by mesoderm |
| Annelida | complete system level; have ectoderm, mesoderm, and endoderm; bilateral symmetry; coelomates; some mobile; examples include earthworms, leeches, sandworms |
| regeneration | the prcess of regrowing missing or damaged body parts |
| sessile | refers to an organism that does not move |
| mobile | refers to an organism that does move |
| amoebocytes | located in the mesenchyme; amoeba-like in shape; some digest food and transport nutrients, other air in reproduction |
| mesenchyme | the middle, jelly-like, layer of a sponge |
| epidermal cells | make up the outer cell layer, or epithelium, of sponges |
| spongin | branched protein fibers that provide flexibility to the sponge "skeleton" |
| gemmule | internal asexual buds of sponges; clusters of specialized amoebocytes protected by a covering of spicules |
| hermaphrodite | an organism that produces BOTH egg and sperm |
| gastrovascular cavity | found in cnidarians; contains only one opening; lined with gastrodermis; where digestion takes place |
| Hydrozoa | the class of cnidarians that contains Hydra |
| Scyphozoa | the class of cnidarians that contains true jellyfish |
| Anthozoa | the class of cnidarians that contains coral and sea anemone |
| tentacles | structures used in getting food; usually around the mouth |
| epidermis | develops from ectoderm |
| gastrodermis | develops from mesoderm |
| cnidocyte | specialized stinging cells located on the tentacles of cnidarian |
| mesoglea | the jelly-like layer between the epidermis and gastrodermis of cnidarians |
| cephalization | the clustering of nerve cells to form an anterior brain; first "seen" in flatworms |
| Turbellaria | class of Platyhelminthes which includes Planaria |
| Trematoda | class of Platyhelminthes which includes flukes |
| Cestoda | class of Platyhelminthes which includes tapeworm |
| eyespots | detect the presence of light |
| Oligochaeta | class of Annelida which includes earthworms |
| Polychaeta | class of Annelida which includes sandworms |
| Hirudinea | class of Annelida which includes leeches |
| setae | bristles that aid the earthworm in moving |
| clitellum | the swollen band around segments 31-37 of teh earthworms; aids in reporduction |
| prostomium | the fleshy overhang covering the earthworm's mouth |
| crop | thin-walled organ that temporarily stores food |
| gizzard | a tough, muscular organ that grinds food |
| closed circulatory system | system where blood is transported within blood vessels |
| aortic arches | the "hearts" of an earthworm |
| nephridium | an organ that filters out excretory wastes the fliud in the coelom |
| parapodia | the appendages found on each segment on organisms in the class Polychaeta |
| longitudinal muscles | when these contract, the segments of an earthworm shorten |
| circular muscles | ring-like muscles that contract to lengthen the segments of the earthworm |
