Aim #80- What are distinguishing characteristics of various groups of organisms in the animal kingdom?
Animal Diversity 1)Vertebrates – animals with a backbone. 2)Invertebrates – animals without a backbone.
Phylum: Porifera Sponges: 1) Lack true tissues & organs. 2) Adult sponges are sessile. 3) Two layers of cells. 4)Reproduce asexually (budding) or sexually. Collar cells – have flagella that trap food particles in mucus. Amoebocytes – pick up food from collar cells, digest it, and carry the nutrients to other cells.
Phylum: Cnidaria Polyp Ex: Hydra Medusa Ex: Jelly 1)Cnidarians have radial symmetry and tentacles with stinging cells. 2)Cnidocytes – are the specialized stinging cells. 3)Nematocyst – stinging capsule inside cnidocyte with stinging barb. Nerve Net: primitive nervous system that provides sensing functions. Gastrovascular Cavity: digestive sac (food enters and waste exits mouth).
Phylum: Platyhelminthes 1)Bilateral symmetry with distinct head and tail. 2) Simplest animals to have three tissue layers (ectoderm, mesoderm, endoderm). 3) Most have Gastrovascular cavity. 4)More complex nervous system (eyes). 5)Flatworms, Planaria, Tapeworms, Blood Fluke. Acoelomate
Phylum: Nematoda 1)Complete digestive tract – has two openings, a mouth and anus, at opposite ends of a continuous tube. 2)Have three tissue layers. 3)Also referred to as roundworms. Pseudocoelomate
Phylum: Annelida 1)Segmented body 2)Distinct head and tail 3)Closed circulatory system 4)Three tissue layers 5) Digestive tract 6) Bilateral symmetry 7) Ventral Nerve cord 8) Earthworm Coelomate
Coelom 1)Acoelomate – animals that lack a body cavity. 2)Pseudocoelomate – fluid-filled body cavity that is in direct contact with the digestive tract. 3) Coelomate – fluid-filled body cavity that is completely lined by mesoderm tissue. (Annelid, mollusk, arthropod, chordota) Simple Complex
Phylum: Mollusca 1)Foot – functions in movement. 2)Mantle – outgrowth of body surface that drapes over animal. Produces shells in clams and snails. 3) Radula – grasping organ used mostly in feeding. 4) Open circulatory system – blood vessels open up into chambers where organs are bathed in blood.
Types of Mollusks 1)Gastropods – single shell that are spiral shaped. Examples: Snails and slugs 2) Bivalves – have hinged shells divided in two halves. Examples: Clams, oysters, mussels, and scallops 3) Cephalopods – small or missing shell. Examples: Octopuses and squids
Phylum: Arthropoda 1)Most numerous and diverse animals. 2)Segmented bodies (head, thorax, abdomen). 3)Jointed appendages 4)Exoskeleton (chitin) 5)Open circulatory system
6) Ventral nerve cord (with ganglia) and brain. 7) Spiracles (holes in the exoskeleton) connect to tracheae (tubes that connect the internal to the external environment) allow for gas exchange in terrestrial arthropods. 8) Malpighian tubules – excretory structures.
Types of Arthropods: 1)Horseshoe crabs 2)Crustaceans- lobsters, crabs, crayfish, shrimp, Barnacles. 3) Arachnids- spiders, scorpions, mites, ticks. 4) Insects- beetles, ants, grasshoppers. 5) Myriapods- centipedes and millipedes.
Phylum: Echinodermata 1)Endoskeleton 2)Water vascular system – a network of water-filled canals that branch into structures called tube feet that function in locomotion, feeding, and respiration. 3) Radial symmetry in adults. 4) Sea stars and sea urchins
Protostomes vs. Deuterostomes Protostomes – coelom forms from solid mass of cells in the embryo. Deuterostomes – coleom forms from a portion of the digestive tube of the early embryo.
Vertebrates vs. Invertebrates Invertebrates – animals without a backbone. Ex: Phyla- Porifera, Cnidaria, Platyhelminthes, Nematoda,Annelida, Mollusca, Echinodermata, Arthropoda Vertebrates – animals with a backbone. Ex: Classes- Fishes, Amphibians, Reptiles, Birds, & Mammals
Vertebrate Characteristics: 1)Skull & Backbone 2)Endoskeleton 3)Hinged jaw
Vertebrates vs. Chordates All vertebrates are chordates, but not all chordates are vertebrates. 4 Characteristics of Chordate Embryos: 1)Notochord 2)Hollow, dorsal, nerve cord 3)Slits in the pharynx 4)Tail Tunicates & Lancelets are the only invertebrate chordates.
Class: Fishes: 1)Cartilaginous Fish – rays and sharks 2) Bony Fish (2 Chambered Heart)
Class: Amphibians: 1)First vertebrates with adaptations to live on land. 2)Larval stage in water (tadpoles), adult stage on land. 3)Adults have lungs to breathe air, moist skin, lack scales. 4) Three-chambered heart. 5) External Fert. & Develop. 7) Ectothermic Examples: Frogs & Salamanders
Class: Reptiles 1)Ectotherms – dependent on the external environment for body heat. 2) Internal fertilization 3) External Development 4) Amniotic eggs 5) Scales 6) Lungs for breathing 7) Three-chambered heart 8) Internal fertilization Ex: Turtles, lizards, snakes, crocodiles, alligators
Class: Birds 1)Endotherms – dependent on cell metabolism to maintain body heat. 2) Wings 3) Feathers 4) Four-Chambered Heart 5) Internal fertilization 6) External Development
Class:Mammals 1)Endotherms 2)Mammary glands 3)Hair 4)Lungs 5)Four-Chambered Heart 6)Internal fertilization 7)Internal Development
Types of Mammals: Monotremes – mammals that lay eggs Ex: platypus Marsupials – “pouched mammals” Ex: kangaroos, koalas, opossums Placental mammals – placenta forms in mother during development. Ex: humans
Order Primates: 1)Binocular vision 2)Flexible shoulder joints 3)Most are tree dwelling 4)Opposable thumbs Ex: Humans, monkeys, apes