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Contribution of Animals Many provide food for us and other animals Clothing and shoes are sometimes made from animal products Research shows that holding or petting a cat or dog slows the heartbeat and blood pressure Offices often have aquariums because sight of fish often relaxes patients 3
Animals can be both good and bad Bees are often considered to be a pest if you have them in your yard But bees are important in pollinating flowers, if you remove the bees you have less flowers Wolves...good or bad? 4
1.) All animals must take in food from their environment (heterotroph) 2.) Animals do not grow beyond a certain adult size 5
3.) Animals are multicellular 4.) Cells have a cell membrane, but no cell wall 5.) Most animals have the ability to move from place to place...this is called locomotion Fly, run, swim, crawl, hop, or slither 6
Some animals only move during early stages of their lives As adults they anchor onto some solid object and remain there Barnacles attach themselves to piers and boats Sponges don't seem to move, but they do have limited movement 7
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Symmetry Symmetry is the balanced arrangement of body parts around a center point or line Starfish have no head or tail, in a circle around a center point This circular body plan is called radial symmetry 9
Most animals, including humans, have bilateral symmetry An animal with bilateral symmetry has its exterior body parts arranged the same way on both sides of its body A dog has two legs on each side A butterfly has one wing on each side 10
Animals with bilateral symmetry usually have a definite front end and back end Anterior = Front end Posterior = Back end Dorsal = Upper side Ventral = Under side 11
Some animals don't have any type of symmetry Asymmetry means "lacking symmetry" You cannot divide them into equal halves 12
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There are two large groups of animals 1.) Vertebrates are animals with backbones The small bones that make up the back bone are called vertebrae The vertebrae are supporting and protecting the spinal cord, which is a bundle of nerves 16
2.) Invertebrates are animals that do not have a backbone Evolved on Earth long before vertebrates Many have shells, or outside skeletons Starfish, jellyfish, grasshoppers, octopuses There are about 41,700 species of vertebrates That might sound like alot...but only 3% of animals are vertabrates 17
Remember... Kingdom Phylum Class Order Family Genus Species Kingdom - Animal Phylum - Vertebrate Invertebrate Class - Fishes Amphibians Reptiles Birds Mammals 18
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Section 2 - Sponges and Cnidarians 20
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A sponge in adult form, is attached to an object in the water and does not move Animals that do not move are called sessile 22
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Spongin is a flexible protein Spicules are very sharp spikes The "skeleton" of a sponge is made up of one of these 24
Sponges can reproduce both sexually and asexually During sexual reproduction an egg cell becomes fertilized by a sperm cell A larva, or young sponge, then develops This larva swims with a flagella to find a permanent home 25
If a small piece of a mature sponge breaks off, it can form a new sponge! This process is called regeneration 26
Coelenterates (Cnidarians) Cnidarians are "baglike" animals that have tentacles arounds their mouths i.e. jellyfish, hydra, sea anemone, and coral Cnidarians have simple tissues, but no organs 27
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Corals have hard skeletons usually made of limestone Coral reefs are created over hundreds of years as living corals life 30
Cnidarians life cycle has two main stages In the polyp stage, the animals body is vase-shaped In the medusa stage, it is bell-shaped 31
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A planarian is a type of flatworm of their body From the mouth they can extend a pharynx, which is a feeding tube 35
Planarians reproduce both sexually and asexually There are no male or female planarians...each planarian produces both egg and sperm cells! Asexual - A small cut off piece of planarian can form a completely new organism...this is called regeneration 36
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Larva hookworms can get into people who walk barefoot in areas where they live The larva is so small it can painlessly enter the body It then enters a blood vessel and makes its way to the lungs It gets coughed up, and swallowed into the digestive tract In the intestines it feeds on blood 39
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An earthworm is a segmented worm There is a large band of tissue near the anterior end of the worm This band is called the clitellum, and is involved in reproduction 42
Earthworms have setae, or tiny bristles, that are located on the ventral side of the worm through the soil 43
The digestive system of a segmented worm consists of the esophogus, a thin-walled crop for storage, and a thick, muscular gizzard for grinding. The rest of the digestive system is an intestine that ends with the anus 44
Segmented worms have blood vessels and "hearts" Earthworms actually have 5 pairs of hearts. The hearts are actually very simple muscles that pump blood into the vessels 45