BIO 120 Objectives 6 Phylum Porifera Exploring Sponges General Zoology BIO 120 Lecture NOVA Loudoun Campus Fall 2013 Chapter 6 Objectives Please respond to the following questions in preparation for the lecture evaluation on this material 1 What is the origin of complex eukaryotic cells What is the theory of endosymbiosis What are two pieces of evidence for this idea 2 What are two advantages of multicellularity What disadvantage do larger cells face 3 To which phylum do sponges belong What does Porifera mean What does Parazoan mean How many species of extant or living sponges are there 4 How many classes of sponges are there NOTE students should know Class Calcarea Class Hexatinellida and Class Demonspongia 5 What are six characteristics of the sponges NOTE students should refer to page 119 6 What are two characteristics of each sponge class 7 What is the aquiferous system 8 What are the osculum choanocytes spicules atrium or spongocoel porocyte mesohyl amoebocyte pinacocyte incurrent pore and pinacoderm NOTE students should refer to Figure 6 4 and be able to illustrate a generalized sponge 9 What are asconoid syconoid and leuconoid sponges NOTE students should refer to Figure 6 8c and be able to illustrate them 10 Is reproduction sexual or asexual or both What are buds and gemmules 1 Theory of Endosymbiosis origin of complex eukaryotic cells Phylum Porifera Exploring Sponges BIO 120 Objectives 6 a Pros increase in size increase in complexity b Cons increased volume less efficient in gas exchange waste removal Mitochondria and chloroplasts Cannot be taken out of cell a b Same size as bacteria c Have double membrane d Reproduce autonomously e Have own DNA 2 Multicellularity absorption etc 3 Sponges a Phylum porifera b Porifera pore bearing c Parazoan side animals d 9 000 10 000 extant species 4 Class of Sponges a Calcarea b Hexatinellida c Demospongia 5 Characteristics of Sponges a Sessile b Porous c No true tissues d Have spicules e Can reproduce asexually or sexually f Asymmetrical g Totipotent cells h Choanocytes water movement 6 Class Characteristics a Calcarea i Calcareous calcium carbonate spicules ii Small iii Mostly found in neritic zone iv Spicules have 2 4 rays v Many are tropical vi Only group that shows all 3 body groups b Hexatinellida i 6 rays on spicules ii Glass sponges spicules fuse iii Often found in deep waters iv Cup shape BIO 120 Objectives 6 Phylum Porifera Exploring Sponges c Demospongia i Salacious spicules ii Spicules have 1 4 rays iii Can be large iv Lots of colorful varieties 7 Aquiferous system water movement flagella of choanocytes beat water from porocyte out of osculum mechanism through which water is moved into throughout and out of sponge 8 Sponge anatomy a Osculum opening at top outcurrent pore b Choanocyte collar pore c Spicule gives structure d Porocyte opening incurrent pore e Mesophyll middle layer matrix f Amoebacyte movile cell transport nutrients can transform to needed cells g Pinacocyte interlaced cells that make up the outer skin layer and provide a Asconoid vase like shape small no folds b Synconoid folded sponge c Leuconoid folds to folds of sponge can be much larger efficient at moving some structure 9 Body groups large volumes of water 10 Reproduction a Asexual i Buds ii Gemmules b Sexual i Sperm and egg