Brief Introduction to the Animal Kingdom
Vocabulary Vertebrate Invertebrate Detritivore Asymmetry Bilateral symmetry Radial symmetry Cephalization Coelum Pseudocoelum Acoelomates Blastula Blastophore Protosome Deuterosome Key Concepts What are the characteristics of an animal? What are essential functions for animals to survive?
Which of these are animals?
Characteristics all animals share: Eukaryotic Multicellular Heterotrophic Reproduce sexually Have specialized tissue that forms nervesand muscles Cells do nothave a cell wall
Diversity in the Animal kingdom is so vast and the differences among the organisms are great Therefore, animals are divided into two major groups Invertebrates Organisms without a backbone Vertebrates (Chordates) Organisms with a backbone 95% of all animals are invertebrates while 5% are vertebrates Invertebrates Vertebrates
How do animals obtain food? Herbivore = eats plants Carnivore = eats animals Omnivore = eats plants and animals Detritivore = feed on decaying organic material Filter Feeders = aquatic animals that strain food from water Parasite = lives in or on another organism Scavenger = consumes carcasses of other organisms
Respiration All animals take in oxygen and give off carbon dioxide Respire through lungs, gills, skin, or simple diffusion Circulation Smaller animals depend on diffusion Larger animals depend on a circulatory system
Excretion: Primary waste product is ammonia Response: Receptor cells = sound, light, external stimuli Nerve cells => nervous system Movement: Most animals move
Reproduction Most reproduce sexually = genetic diversity Many invertebrates can also reproduce asexually to increase their numbers rapidly
Body Symmetry Body Symmetry the body plan of an animal, how its parts are arranged Types of Symmetry Asymmetry -no pattern (corals, sponges) Radial Symmetry -shaped like a wheel (starfish, hydra, jellyfish) Bilateral Symmetry -has a right and left side (humans, insects, cats, etc)
Cephalization-an anterior concentration of sense organs (to have a head) Animals with bilateral symmetry tend to exhibit cephalization The more complexthe animals becomes the more pronounced their cephalization
Body Sides anterior -towards the head posterior -towards the tail dorsal -back side ventral-belly side
Segmentation "advanced" animals have body segments, and specialization of tissue (even humans are segmented, look at the ribs and spine) Segmented
Body Cavity Most animals have some type of body cavity A fluid-filled space between digestive tract and body wall Allows digestive organs to grow Coelum(prounounced see lum ) Body cavity that develops within the mesoderm and is completely lined with tissue derives from mesoderm More complex organisms have
Pseudocoelum Body cavity is partially lined with mesoderm Example: Pinworm Acoelomate Organism lacks body cavity all together Examples: Jellyfish, tapeworms
Animal Development Early Development Animals begin life as a zygote(fertilized egg)
The cells in the zygote divide to form the BLASTULA-a hollow ball of cells
The blastula pinches inward to form three GERM LAYERS Ectoderm: Outermost layer Develops into the sensory organs, nerves, outer layer of skin Mesoderm: Middle layer Develops into the muscles, most of the circulatory system, reproductive system, and excretory organ system reproductive system, and excretory organ system Endoderm: Innermost layer Develops into the digestive system and much of respiratory system
Blastophore: digestive tract that only has one opening to outside Protosomes: an animal whose mouth is formed from the blastophore Example: most invertebrates Deuterosomes: an animal whose anus is formed from the blastophoreand the mouth is formed for a second opening later in development Examples: Echinoderms and Chordates
Animal Kingdom Phyla Phylum Porifera sponges Phylum Cnidaria sea anemones, jellyfish, hydra
Phylum Platyhelminthes- Flatworms (e.g. tapeworms, planarian) Phylum Nematoda roundworms (e.g. pinworm) Phylum Annelidasegmented worms (e.g. earthworms) Tapeworm Pinwor rm Earthworm
Phylum Molluska clams, squid snails
Phylum Arthropoda-crustaceans, insects, spiders This is the largest phylum in the animal kingdom and contains the most number of species
Phylum Echinodermata starfish Phylum Chordata all vertebrates