11/04/2011 Section 6.3: Kingdom Animalia pg. 182-197 Part 1: Invertebrates Animal Kingdom • Includes the very small to the very large organisms on Earth. • Animals: – are multicellular eukaryotes – are heterotrophic – reproduce sexually 1 11/04/2011 Animal Characteristics These are used to classify animals into different phyla: 1. The number of Germ Layers – “germ” = cells in early stages – Most have 3 layers: ectoderm (outer), endoderm (inner) & mesoderm (middle) 2. Digestive Tract – Most animals use extracellular digestion – Incomplete digestive tract : only one opening (food & wastes use the same opening) – Complete digestive tract : separate openings for food & wastes. 2 11/04/2011 3. Body Symmetry – Asymmetrical Body : irregular shape (i.e. sponges, who are the simplest animals) – Symmetrical Body : most animals are balanced in their shape Symmetry There are 2 types of symmetry 1. Radial (Fig. 6.17a, pg. 185) 2. Bilateral (Fig. 6.17b, pg. 185) 4. Development of a Coelom – Coelom = a fluid-filled body cavity – The presence of a coelom allows for the development of more complex organ systems. – Animals with a coelom = coelomates – Animals without a coelom = acoelomates 3 11/04/2011 5. Reproduction – All animals reproduce sexually – Some also reproduce asexually – Some are hermaphrodites = have both male & female reproductive organs Invertebrates (95% of Animal Kingdom) • Examples include: (see Table 6.2, pages 183-184) – sponges – sea anemones – jellyfish – coral – planarians – tapeworms – leech – slug – clam – octopus – starfish – sand dollars, etc. Invertebrate Characteristics • Lack of internal structures • Reproduction includes sexual & asexual • Some are coelomate (i.e. earthworm) & some are acoelomate (i.e. flatworm) 4 11/04/2011 Invertebrate Characteristics • Can have asymmetrical (i.e. sponges), radial (i.e. jellyfish) or bilateral body forms (i.e. earthworm). There are over 30 phyla of invertebrates, but we will look at the major eight. 8 Phyla of Invertebrates 1. Porifera 2. Cnidaria 3. Platyhelminthes 4. Nematoda 5. Annelida 6. Mollusca 7. Echinodermata 8. Arthropoda 5 11/04/2011 Phylum Porifera • Means “pore-bearing” • Example: Sponges Phylum Cnidaria • Means “thistle” • Examples: Jellyfish, corals, sea anemones, hydras Phylum Platyhelminthes • Means “flat, wide worms” • Examples: Tapeworms, flukes, planarians 6 11/04/2011 Phylum Nematoda • Means “thread-like” • Examples: Pinworms, hookworms Phylum Annelida • Means “ring” • Examples: Earthworms, leeches, tubeworms Phylum Mollusca • Means “soft-bodied” • Examples: clams, oysters, squids, octopi, snails, slugs, scallops 7 11/04/2011 Phylum Echinodermata • Means “spiny-skinned” • Examples: starfish, sea cucumbers, sand dollars, sea urchins Phylum Arthropoda • The MOST successful phylum!! • Over 1 million species have been identified. • Very diverse – some live at the bottom of the ocean, and some float in the air. Examples of Arthropods • Include: – Insects – Spiders – Shrimp – Barnacles – Lobster – Scorpions 8 11/04/2011 Arthropods… • have jointed appendages • have bilateral symmetry • have a coelom • have a “tube within a tube” digestive system • reproduce sexually Why are Arthropods So Successful? • Exoskeleton: – a rigid, jointed external skeleton – is waterproof and protects against water loss – they must shed their exoskeleton in order to grow. Other Reasons Why They Are Successful… • The nature of their body segments & attached appendages. • Their well-developed nervous system. • Their structures & functions related to feeding themselves. 9 11/04/2011 Insects • The most successful species on Earth. • But Why??? 1. They have many adaptations for feeding. 2. Most are small in size, allowing them to hide. 3. They move quickly and many have wings. Insect Mimicry • Some insects have an adaptation called mimicry. • Mimicry: the ability to look like something else. Two Short Videos • Insect Mimicry • Phylum Arthropoda “How Stuff Works” 10 11/04/2011 Section 6.3: Part 1 Review Activities • Do the “Survey of Invertebrates” handout. • Go to lab to do the Investigation 6C on pages 188-189. 11 .