BIO 172 UH Manoa Exam 2 Latest Update Graded A+

BIO 172 UH Manoa Exam 2 Latest Update Graded A+ Animals Multicellular eukaryotes Heterotrophs: Ingest their food Lack Cell Walls Body held together by structural proteins Collagen Make up connective tissues (fibers) Flexible and high tensile (stretching) Skin Dense irregular arrangement of collagen Ligament Collagen arranged in sheets (Connects Bones) Tendon Cable-like arrangement of collagen (Connects muscle to bone) Zygote Fertilized egg (Sperm+Egg=Zygote) Undergoes rapid cell division called cleavage Germ Layers Give rise to tissues and organs of animal embryo Blastula Cell that has undergone many cell cleavages Hollow blastula undergoes gastrulation, forming gastrula (has layers of embryonic tissues) Ectoderm Germ layer covering embryo surface Endoderm Innermost germ layer and lines developing digestive tube (aka=Archenteron) Diploblastic Animals that exhibit both ectoderm and endoderm in the embryo (Corals, jellyfish) Triploblastic Animals that have intervening Mesoderm layer (bilaterians) Bilaterians All Multicellular animals other than sponges and cnidarians Exhibit bilateral symmetry and cephalization Cephalization Organization of senses and locomotion toward head region Larva Sexually immature and anatomically distinct from the adult, undergoes metamorphosis Juvenile Resembles an adult, but not sexually mature Cambrian explosion 535-525 million years ago, marks earliest fossil appearance of many animal major groups Hox Genes Control the development of body form (Hox Gene "__" can tell to form an arm) Protosome Cell proliferation by spiral cleavage Coelom forms within the middle tissue germ layer Initial opening of gut becomes the mouth Deuterostome Cell proliferation by radial cleavage Coelom forms from outpocket of the middle tissue germ layer Initial opening of gut becomes the anus Coelom Body cavity surrounding the gut Sessile Do not exhibit locomotion (Sponges) Collar Cells Flagella bearing cells that create water currents that move through the body of the sponge Spicules Tiny calcium/silica structures Sponges (Phylum:Porifera) Hermaphrodites (release sperm into environment) Jellyfish, Anemones, Corals (Phylum: Cnidaria) Have radial symmetry Possess two specialized cell layers (tissues) and nerve cells Two Body Forms: Sessile polyp and free swimming