Transcript CHAPTER 7
CHAPTER 7 Animal classification Key science words vertebrate invertebrate symmetry TRAITS OF ANIMALS Animals are consumers Must take in food from their surroundings Some animals eat plants, others eat other animals Animals digest and store food in their bodies Most animals can move from place to place Animals are multicellular organisms Cells are grouped into tissues and organs that form systems Most animals have a nervous, digestive, and reproductive system TWO GROUPS OF ANIMALS Vertebrates animals with backbones fish, amphibians, reptiles, birds Invertebrates animals without a backbone worms, and insects SYMMETRY BALANCED ARRAINGEMENT OF BODY PARTS AROUND A CENTER POINT OR ALONG A CENTER LINE Two types of symmetry Radial Bilateral SYMMETRY Radial Body parts are arranged in a circle around a central point Ex. A sea anemone fig 7-1b SYMMETRY Bilateral The body can be divided lengthwise into two equal sides, a right side and a left side This includes all vertebrates and some invertebrates The animal must have a head and a tail end, and an upper and lower half REVIEW OF TRAITS 1. Animals can’t make food, they must catch it and eat it 2. Most animals can move from place to place 3. Animals have many cells 4. Most animals have some type of symmetry 9 MAJOR GROUPS OF CLASSIFICATION Sponges, stinging celled animals, 3 worm phyla, soft-bodied animals, jointed-leg animals, spiny skinned animals, chordates Sponges are the smallest phyla, jointedleg animals are the largest, refer to fig. 7-2 SPONGES AND STINGINGCELLED ANIMALS Simple Invertebrates Have pores Do not move on their own Live in salt and fresh water Water comes in through the pores and out through a hole at the top center of the body, food from the water gets trapped by food getting cells inside the body SPONGES CONT. Two cell layers thick Have no muscles or nerve cells No tissues, organs, or organ systems Reproduce sexually or asexually, by egg and sperm, or by budding Sponges are asymmetrical lacking symmetry STINGING-CELLED ANIMALS Animals with stinging cells Hollow sac-like bodies Lack organs Live in the ocean and in fresh water Examples: jellyfish, coral, sea fan Stinging-celled cont. Have arm-like parts call tentacles that surround the mouth Have RADIAL symmetry A body cavity contains an opening called the mouth It’s the only way into and out of the body Stinging-celled cont Attach themselves to the ocean bottom with or to rocks with a structure called a disc Do not move from place to place How do they catch their food? With their tentacles WORMS Worms are invertebrates 3 phyla---flatworms, roundworms, segmented worms We Tentacles contain poison darts that stuns the animal that touches them Food enters through the mouth and undigested food leaves through the mouth Reproduce sexually and asexually FLATWORMS Simplest worms Flat body, 3 layers of cells, outer, middle, and a thick middle layer Most flatworms are parasites Parasites live in or on other living things getting food from them (called the host) TAPEWORM Flat ribbon-like body divided into sections Live in the intestine of almost any kind of vertebrate Have suckers and hooks that hold onto the sides of the intestine They absorb food that has already been digested TAPEWORM CONT. Tapeworms in humans are not as common as in other countries In the us waste is treated with chemicals at sewage plants Meat is inspected for cysts However always cook your meat well Copy down the life-cycle of a tapeworm into your notes pg 143 ROUNDWORMS Have long bodies with pointed ends 3 layers of cells Some cannot be seen without a microscope Many are parasites Hosts are people, dogs, cats, plants ROUNDWORMS CONT Found in the soil Hookworms are parasites of people, they enter through the skin of the feet, once inside they move to the intestine, and feed on the hosts blood Refer to figure 7-11 ROUNDWORMS CONT Have long rounded bodies Has a mouth and an anus (first animal to have a 2 way gut) First animal to have an intestine Males and females are separate animals, first animal to have separate sexes SEGMENTED WORMS Bodies divided into sections called segments 3 cell layers Most complex of the worms Live in salt water, fresh water and on land Ex: leech, earthworm SEGMENTED WORMS CONT Segments have muscles Have a mouth and an anus Has an intestine Two blood vessels 5 pairs of simple hearts that carry oxygen and food to all the cells Has nerves and a simple brain Separate sexes SOFT-BODIES ANIMALS Soft body protected by a hard shell Body covered by a thin fleshy tissue called a mantle (mantle makes the shell) Have a muscular foot for moving Have a head with a mouth with teeth 1st CLASS OF SOFT-BODIED ANIMALS Snails and slugs Live on land and in the water Glide using a muscular foot snails(shell) slugs(no shell) Snail has two tentacles (sense organs) Contain eyes that detect light 2nd class Clams, oysters, scallops Have two shells that fit together Have a muscular foot Live buried in the sand and filter water to get food 3rd class Octopus, squid, cuttlefish Squid, cuttlefish have shells inside their bodies Octopus has no shell Have tentacles surrounding the head Well developed eyes Rapid swimmers Features of soft-bodied animals review 1 all are invertebrates 2 soft body covered by a mantle 3 most have 1 or 2 external shells, or an internal shell 4 most have a foot by which they move about will consider the 9 phyla shown below.