INVERTEBRATES AND VERTEBRATES By: Willie Johnson and Lauren Conerly Ap biology 5th pd.

Animal Classification Animal Kingdom Invertebrates ( No backbone) Vertebrates (Backbone) Cnidarians Roundworms Annelids Echinoderms Chordates Sponges Flatworms Mollusks Arthropods

What is an Invertebrate? Invertebrates are organisms that do not have backbones. 95% of the animal kingdom is made up of invertebrates.

Symmetry Arrangement of the individual parts of an organisms Radial Bilateral Asymmetrical Body parts arranged in a circle around a central point Parts are mirror images of each other Bodies cannot be divided into matching halves

Cnidaria: Corals, Hydras, and Jellyfish

Cnidaria Characteristics Cnidaria comes from the Greek word nettle All cnidarians have stinging cells called nematocysts in tentacles surrounding their mouths They come in two body shapes: Polyp: usually attached to the vase Medusa: free-swimming and bell-shaped

Cnidaria Characteristics Cnidarians reproduce both sexually and asexually Polyp forms reproduce asexually by budding Some polyps also reproduce sexually be releasing sperm or eggs Medusa forms have a two-stage life cycle in which they reproduce both sexually and asexually

JELLYFISH HYDRAS They live in fresh water. They spend most of They spend their entire life as polyps. Hydras have tentacles that catch their food. They move from place to place. Hydras are very small animals. Reproduce asexually by budding. They spend most of their life as medusa. They swim. Jellyfish catch shrimp, fish, and other animals in its tentacles also. Reproduces sexually to produce polyps; then each polyp reproduces asexually to form new meduae

Platyhelminthes: Flatworms Roundworms Segmented Worms

Mollusks Gastropods – most have one shell Live in water or on land Move by gliding their large muscular foot along a trail of mucus

Arthropoda Characteristics Arthropods are a group of invertebrates with jointed appendages, such as claws, legs, and antennae, and a hard exoskeleton. They also have bilateral symmetry. They are the only invertebrates that can fly Includes Insects, Spiders, Ticks, Mites, Centipedes, Millipedes, Crustaceans

What’s a vertebrate? WHAT’S A CHORDATE? A chordate animal with a backbone: Mammals, reptiles, amphibians, shark rays, ray-finned fishes, lobe-fins WHAT’S A CHORDATE? Animals that at some point have a notochord, dorsal hollow nerve chord, pharyngeal slits/clefts and a muscular post-anal tail

Dorsal hollow nerve chord PHARYNGEAL SLITS/Clefts NOTOCHORD Dorsal hollow nerve chord PHARYNGEAL SLITS/Clefts A longitudinal, flexible rod that runs along the anterior-posterior axis in the dorsal part of the body It provides skeletal support Present in all embryos and some adults Develops into the central nervous system (brain and spinal chord) Clefts- One of the grooves that separate the pouches along the pharynx Slits- Form from clefts, communicate to the outside and can develop into gill slits or into the jaw and inner ear in terrestrial animals.

ORIGIN OF VERTABRATES Vertebrates made their fist appearance approximately 530 million years ago, thought to derive from the aquatic chordate Myllokunmingia Genomic and fossil evidence suggests that vertebrates evolved from craniate which evolved from invertebrate chordates. Most likely that lancelets diverged from tunicates and vertebrates diverged from lancelets

LANCELET TUNICATE CRANIATE Small blade shaped marine chordate lacking a backbone Sessile marine chordate lacking a backbone Chordate with a head

QUIZ

QUESTION 1 What percentage of the animal kingdom is made up of invertebrates? A.) 50 % B.)37% C.)80% D.)95%

QUESTION 2 Bodies that cannot be divided into matching halves are called: A.) Symmetrical B.)Bilateral C.)Asymmetrical D.)Radial

QUESTION 3 Vertebrates are thought to specifically derive from: A.) Marine life B.) Lancelets C.) Tunicates D.)Craniate

QUESTION 4 What is a notochord? A.) It develops into the central nervous system B.) One of the grooves that separate the pouches along the pharynx C.) A longitudinal, flexible rod that runs along the anterior-posterior axis in the dorsal part of the body D.) Form from clefts, communicate to the outside and can develop into gill slits or into the jaw and inner ear in terrestrial animals.

QUESTION 5 Name 3 examples of invertebrates and 3 examples of vertebrates