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Download Fungi - Mrs. Dedam
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Animal Diversity multicellular, heterotrophic, eukaryotic organism with tissues that develop from embryonic layers Cell Structure • Eukaryotic • No cell walls, held together w/ structural proteins collagen • Specialized cells (muscle, nerve) Reproduction and Development • Diploid- produce gametes • Most reproduce sexually – Asexual-self fertilize • Embryo forms blastula (hollow ball of cells) • Blastula develops BlastoporeGastrula • Cell layers develop Animal history • Colonial heterotrophic protists • Hollow sphere of cells • Reproductive cells fold inward • Specialization of germ layers Animals can be characterized by symmetry, tissues and body cavities • Symmetry – Radial sea anemone • sessile – Bilateral lobster • • • • • Dorsal-top Ventral-bottom Anterior-head Posterior-tail Generally active • Cephalization- sensory nerves concentrated in the anterior end of the organism • Tissues – Germ layers- concentric layers of tissue • Ectoderm- outside – Skin, hair, nails • Endoderm- inside – Stomach, intestine, lungs, liver • Mesoderm- middle – Muscle Diploblastic: 2 germ layers ex. jellyfish Tribloblastic: 3 germ layers ex. Bilaterally symmetrical • Body Cavities – Coelom=fluid filled space that separates the digestive tract from the outer body wall – True coelomtissue that surrounds and supports internal organs, forms fluid cavity • Body cavity protects organs, allows them to move without moving the whole organism, acts as an internal skeleton • Acoelomate- no body cavity, solid • Pseudocoelomate- mesoderm doesn’t fully surround organs, has fluid filled space Protostomes and Deuterostome Development • Cleavage- organization of early cell divisions – Protostomes have spiral cleavage, early determination – Deuterostomes have radial cleavage, early cells are indeterminate • Coelom formation– Protostomes- mesoderm forms as a solid mass that engulfs the coelom – schizocoelous – Deuterostomes- mesoderm forms from blastopore – enterocoelos • Fate of blastopore – Protostomes- blastopore develops into mouth – Deuterostomes- blastopore develops into anus • Protostomes – Shellfish – Insects – Earth worms • Deuterostomes – Starfish – Vertebrates Animal Phylogeny: Points of Agreement • All animals share a common ancestor • Sponges are basal animals- lack true tissues, most distantly related to other animals • All other animals are “true animals” because they have true tissues • Jellyfish lack bilateral symmetry and are therefore the most distantly related “true animals” • Vertebrates are deuterostomes
