Invertebrates Unit 7
Introduction to Animals Chapter 24 Big Idea: Animal phylogeny is determined in part by animal body plans & adaptations.
24.1 Animal Characteristics Main Idea • Animals are multicellular, eukaryotic heterotrophs that have evolved to live in many different habitats.
General Animal Features • Kingdom Protista • Algae, Protozoans, Euglenoids
Feeding & Digestion • Animals are heterotrophic. • The structure or form of an animal’s mouth parts determines how its mouth functions.
Support • Invertebrates • Exoskeletons • Hard or tough outer coverings that provide a framework of support • Protect soft body tissues • Provide protection from predators
Support • Vertebrates • Endoskeletons • Protect internal organs • Provide support for the body • Provide an internal brace for muscles to pull against
Movement • The evolution of nerve and muscle tissues enables animals to move in ways that are more complex and faster than organisms in other kingdoms.
Reproduction • Early Development
Reproduction • Tissue Development
24.1 Vocabulary • Blastula • Ectoderm • Endoderm • Endoskeleton • External fertilization • Gastrula • Hermaphrodite • Internal fertilization • Invertebrate • Mesoderm • Vertebrate • Zygote
24.1 Key Concepts • Animals must get their nutrients from other organisms. • Animals have diverse means of support and live in diverse habitats. • Animal cells do not have cell walls, and most animals have cells that are organized into tissues. • Most animals undergo sexual reproduction, and most animals can move. • During embryonic development, animal cells become tissue layers, which become organs and systems.
24.2 Animal Body Plans Main Idea • Animal phylogeny can be determined, in part, by body plans & the ways animals develop.
Foldable • Title: Body Plans • Coelomate • Psuedocoelomate • Acoelomate
Symmetry • Asymmetry • Radial Symmetry • Bilateral Symmetry • Cephalization
Body Cavities • Coelomates • Have a fluid-filled cavity with tissue formed from mesoderm that lines and encloses the organs in the coelom
Body Cavities • Pseudocoelomates • Have a fluid-filled body cavity that develops between the mesoderm and the endoderm rather than developing entirely within the mesoderm
Body Cavities • Acoelomate • Have solid bodies without a fluid-filled body cavity between the gut and the body wall
Development in Coelomate • Protostomes • The mouth develops from the first opening in the gastrula. • Deuterostomes • The anus develops from the first opening in the gastrula.
Segmentation • Segmented animals can be “put together” from a succession of similar parts. • Can survive damage to one segment • Movement is more effective
24.2 Vocabulary • Acoelomate • Anterior • Bilateral symmetry • Cephalization • Coelom • Deuterostome • Dorsal • Posterior • Protostome • Pseudocoelom • Radial Symmetry • Symmetry • Ventral
24.2 Key Concepts • Animal phylogeny can be compared to a tree with branches. • The branches of a phylogenetic evolutionary tree show the relationship among animals. • Animal phylogeny can be determined, in part, by the animal’s type of body cavity of lack of body cavity. • After gastrulation, two types of development can occur in coelomate animals. • Segmentation is an important feature in some coelomate animals.
24.3 Sponges & Cnidarians Main Idea • Sponges & cnidarians were the first animals to evolve from a multicellular ancestor.
Sponges • Body Structure • Support • Feeding & Digestion • Response to Stimuli
Reproduction • Asexual • Fragmentation • Budding • Gemmules • Sexual • Hermaphrodite
Sponge Diversity • Sponge Ecology
Body Structure • Have one body opening and two layers of cells • Outer layer functions in protecting the internal body • Inner layer functions mainly in digestion
Feeding & Digestion Response to Stimuli • Tentacles are armed with stinging cells called cnidocytes. • A nematocyst is a capsule that holds a coiled tube containing poison and barbs. • A barb is capable of penetrating a crab shell.
Feeding & Digestion • Cells lining the gastrovascular cavity release digestive enzymes over captured prey • Undigested materials are ejected though the mouth.
Reproduction • Two body forms: • Medusa • Polyp
Cnidarian Diversity • Hydroids • Jellyfishes • Sea Anemones & Corals
24.3 Vocabulary • Cnidocyte • Filter feeder • Gastrovascular cavity • Medusa • Nematocyst • Nerve net • Polyp • Sessile
Key Concepts • Sponges can be described according to animal features they do not have and according to the feature they do have. • Sponges do not have tissues, but carry out the same life functions as other animals. • Cnidarians have unique features that other animals do not have. • Cnidarians have more highly evolved body forms and structures than sponges. • Sponges and cnidarians are important to the ecology of their habitats and to humans.
Worms & Mollusks Chapter 25 Big Idea: Worms & mollusks have evolved to have a variety of adaptations for living as parasites or for living in water or soil.
25.1 Flatworms (Platyhelminthes) Main Idea • Flatworms are thin, flat, acoelomate animals that can be free-living or parasitic.
Body Structure • Feeding, Digestion, & Excretion
Body Structure • Respiration & Circulation • At the Cellular Level • Response to Stimuli • Nerve cords & Ganglion • Movement • Cilia • Reproduction • Hermaphrodite • Regeneration
Diversity of Flatworms • Turbellarians • Planarian! • Trematodes • Flukes • Cestodes • Tapeworms
25.1 Vocabulary • Flame cell • Ganglion • Pharynx • Proglottid • Regeneration • Scolex
Key Concepts • Flatworms were among the first animals to exhibit bilateral symmetry. • Flatworms are acoelomates with limited numbers of organs and systems. • Some flatworms are free-living, & others are parasitic. • The 3 main classes of flatworms are Turbellaria, Trematoda, and Cestoda. • Flatworms that are parasitic have specialized adaptations for parasitic life.
25.2 Roundworms & Rotifers Main Idea • Roundworms & rotifers have a more highly evolved gut than flatworms derived from a pseudocoelomate body plan.
Body Structure of Roundworms • Feeding & Digestion • 1-way track • Respiration, Circulation, Excretion, & Response to Stimuli • Movement • Long side muscles • Hydrostatic Skeleton • Reproduction
Diversity of Roundworms • Trichinella Worms • Hookworms • Ascarid Worms • Pinworms • Filarial Worms • Nematodes in Plants
Rotifers • Rotifer Features & Movement • Organ Systems of Rotifers
25.2 Vocabulary • Hydrostatic skeleton • Trichinosis
Key Concepts • Roundworms are closely related to flatworms, but roundworms have an evolutionary adaptation related to their gut. • Roundworms, like flatworms, have a limited number of organs & systems. • Roundworms are either free-living or parasitic. • Roundworms cause many human & plant diseases. • Rotifers are pseudocoelomates that appear on a different branch of the evolutionary tree than roundworms.
25.3 Mollusks Main Idea • Mollusks are coelomates with a muscular foot, a mantle, & a digestive tract with 2 openings.