Biology 1402 Test 3 Held Latest Version Graded A+

Biology 1402 Test 3 Held Latest Version Graded A+ Larva An early stage in the life cycle of an organism that will undergo complete metamorphosis. Metamorphosis A marked change in form, character, or function; a transformation Invertebrate An animal without a backbone Vertebrate An animal with a backbone Bilateral symmetry Body plan in which only a single, imaginary line can divide the body into two equal halves. Coelom Body cavity Cephalization concentration of sense organs and nerve cells at the front of an animal's body Get a head Radial symmetry Symmetry about a central axis. pseudocoelom body cavity between the endoderm and mesoderm tissues that is partially lined with mesoderm tissue segmentation subdivide main axis of body into stripes, Body is made up of a series of fused rings; external and internal structures are repeated segment by segment 2-ended gastro-intestinal tract= mouth-anus sac-like gut only one opening for both waste and food Porifera (pores)* Ex: Sponges sessile (stationary) filter feeders, supportive extracellular matrix, sac-like gut, vase shaped incurrent pores(water exits via mouth), Choanocytes( ciliated cells = human lungs), amoebocytes (crawling cells=macrophages) Cnidaria (needle)* Ex: Jellyfish, hydras, corals, sea anemones shaped like vases (polyps) or umbrellas(medusa) Nerves= loose network Bizarre= Regenerate lost parts Mythology= hydra & medusa Platyhelminthes (flat worms)* Ex: flatworms, tapeworms Head: "brain" senses for light, chemicals, pressure GPP/Evol: constraint: small Bizarre= mouth=navel Nematodes* Roundworms