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Introduction to Animals
Characteristics
Multicellular Organization
Heterotrophic Sexual
reproduction and development Movement
Animal Classes
Mammals
People are mammals. So are dogs, cats, horses, duckbill platypuses, kangaroos, dolphins and whales. What do all these animals have in common, you ask?
The answer is – MILK! If an animal drinks milk when it is a baby and has hair on its body, it belongs to the mammal class
Mammals are one of the 6 main classes of animals. Animal classes are groups of animals that scientists consider to be alike in some important ways. Mammals are the animal class that people belong to.
Multicellular Organization
Most animals contain large numbers of cells.
Humans contain 50 trillion cells.
Reptiles
Reptiles areຫໍສະໝຸດ Baidua class of animal with scaly skin. They are cold blooded and are born on land.
Snakes, lizards, crocodiles, alligators and turtles all belong to the reptile class.
There are only about 4,000 kinds of mammals. Warm-blooded
Birds
Birds are animals that have feathers and that are born out of hard-shelled eggs.
Some people think that what makes an animal a bird is its wings. Bats have wings. Flies have wings. Bats and flies are not birds. So what makes an animal a bird?
Amphibians
Amphibians are born in the water. When they are born, they breath with gills like a fish. But when they grow up, they develop lungs and can live on land.
The answer is feathers! All birds have feathers and birds are the only animals
that do. The feathers on a bird’s wings and tail overlap. Because they overlap, the feathers catch and hold the air. This helps the bird to fly, steer itself and land.
Fish
Fish are vertebrates that live in water and have gills, scales and fins on their body. There are a lot of different fish and many of them look very odd indeed. There are blind fish, fish with noses like elephants, fish that shoot down passing bugs with a stream of water and even fish that crawl onto land and hop about!
Arthropods
Arthropods is a huge phylum of animals -- it includes eleven animal classes: Merostomata, Pycnogonida, Arachnida, Remipedia, Cephalocarida, Branchiopoda, Maxillopoda, Malacostraca, Chilopoda, Diplopoda, and Insecta.
Any animals that have more than four, jointed legs are arthropods. Insects, spiders and crustaceans all belong to this class of animals.
Zoologist Arachnologist Carcinologist Conchologist Entomologist Herptologist Ichthyologist Malacologist Mammalogist Ornithologist Paleozoologist Marine biologist botanist
