Biology Lab 1106 Baylor University Exam 3 with 100% correct answers

Phylum Porifera (sponges) asymmetrical lack true tissues have unique cells called CHOANOCYTES (flagellated cells that will draw in water and filter food particles) Genus: Grantia, Spongia, Euplectella Phylum Porifera Genus Grantia isolated spicules walls of sponges contain amoebocytes and crystallized structures called spicules incurrent canals and flagellated canals 00:00 01:22 Phylum Porifera Genus Spongia have spongin fibers that are more flexible live specimen Phylum Porifera Genus Euplectella live specimen of Porifera Phylum Cnidaria radial symmetry true tissues 2 germ layers (Endoderm and ectoderm) have stinging cells (cnidocytes) involved in predation polymorphic Classes: Hydrozoa, Scyphozoa, Anthozoa Polymorphic alternate between polyp and medusa stage classes are characterized by which morph is dominant Common Life Cycle of Cnidaria 1. Medusa produce and release eggs and sperm into water for fertilization (some retain eggs) 2. Zygote develops into a swimming mass of ciliated cells called the planula larva 3. Planula will settle to a substrate and develop into a polyp 4. Polyp may reproduce asexually by budding other polyps or continue the sexual cycle by budding immature medusae called ephyrae 5. Ephyrae develop into mature medusa Class Hydrozoa polyp morph dominates Genus: Hydra, Obelia, Physalia Class Hydrozoa Genus Obelia polyp colony and small free-swimming medusa whole mount slide showing colony gastrozoids and gonozoids