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Classification of Plants & Animals

At any one time in history, there are millions of different kinds of plants and animals in the world. In 1753, a scientist in Sweden named Carolus Linnaeus thought of an orderly system for classifying plants and animals. He grouped all organisms according to a two-part name (binomial). The first part of the name is the "generic" grouping or genus. The second part is the "specific" grouping or species. Scientists today still use this basic idea of his system, but modern classifications systems are much more complicated having many levels of hierarchical organization. For example, taxonomic systems group organisms according to structure and physiological connections between organisms. Phylogenic systems classify based on genetic connections. Evolution theories have impacted modern classification.: Biological Classification; Tree of Life; Animal Kingdom Taxonomy; Animal Bytes

Classified!
Go classification crazy and start grouping and sorting your world.

In order to begin to classify plants, consider the structure by which the plant absorbs water. Plants are either vascular or non-vascular. Vascular plants have tube-like structures that transport water from the roots to the stem to the leaves. Non-vascular plants absorb water only through their surfaces.: Leaf Structure; Dandelion; Hydroponics; Mold/Fungus; Lichens; Fungi Facts; Microworlds; Natural Perspective; Antibiotic; Scott's Botanical Links; Botanical Society of America; Web Garden; The Great Plant Escape

Vascular Vegetables
Use common vegetables to observe the vascular structure and nature of plants.

Another way to consider plant classification is according to reproduction. Some plants reproduce by producing seeds. Others produce spores.: Plant Science Institute; Plant Galls
To begin to classify animals, consider the backbone. Animals that have a backbone are called vertebrates. Animals that do not have a backbone are called invertebrates.
All invertebrates lack backbones, but their other physical characteristics are quite varied. They must be, considering that 95 percent of all animals are invertebrates. Some, like worms, have soft bodies with no bones at all.: Earthworms; Worms
Some other invertebrates, like snails, have soft bodies, but carry a hard shell for protection. These soft-bodied invertebrates that live in water or on land are grouped as mollusks. Besides snails, some other mollusks are clams, mussels, and squid.: Clams; Zebra Mussel Information Resources; The Zebra Mussel Page; Invertebrates of The Sea
Some other invertebrates have tough coatings on the outside of their bodies (exoskeletons), jointed legs, and a segmented body. This group is known as the arthropods. Insects, spiders (arachnids), centipedes/millipedes, and shrimp, lobster, and crabs (crustaceans) are all arthropods. There are more insects (over 900,000 species) than any other group of arthropods. There are more arthropods than any other group of invertebrates. And, considering that 95 percent of all animals are invertebrates, that makes arthropods truly the must abundant group.: Wonderful World of Insects; 3-D Insects; Spotlight on Insects; Hotlist - Insects; Entomologist; Insects; Minibeast World
One particularly popular member of the insect world is the butterfly. This arthropod, with its tough outer shell, characteristic wings, and antennae, belongs to the insect family.: Monarchs and Migration; Monarch Watch; Monarch/Viceroy Mimicry; Entomology for Beginners - Metamorphosis; Butterfly Pavillion and Insect center; The Butterfly Website; Painted Lady and Red Admiral Butterflies; Thinking Fountain; Journey North; The Butterfly Farmer; Caterpillars & Butterflies; The South Carolina Butterfly Project

All vertebrates have a backbone. Their other physical characteristics are quite varied. One way to consider groups of vertebrates is according to their diet. Animals that primarily eat plants are known as herbivores. Animals that feed mostly on meat are known as carnivores. Some animals, called omnivores, eat both plants and meat.
An animal's eating habits are influenced by its anatomy. Meat-eaters have jaws and teeth designed for tearing and crushing. The canine teeth are enlarged and the molars have sharp cusps. The intestinal tract is adapted for handling quick digestion of meat. Plant-eaters usually have large incisors for cropping and cutting plants. Their large, ridged molars are adapted for grinding tough plant fibers and their intestines are rather long, allowing for slow digestion of plant fibers.: Hotlist - Animals; Vertebrate Flight; The Electronic Zoo; Zoo TV; The Lincoln Park Zoo - Virtual Zoo and Live Images; Carnivorous Plants
Another way to consider groups of vertebrates is according to their body temperature. All vertebrates are either cold-blooded or warm-blooded. A vertebrate is considered cold-blooded if its internal body temperature matches the external temperature around it. Fish, amphibians and reptiles are examples of cold-blooded animals. Their dependence on the water or land makes it necessary for them to adapt to the temperature surrounding them.: Reptiles: Real and Robotic; Salmon Page; Fish Information Service; Lincoln Park Zoo - Reptiles and Amphibians; Jurassic Frogs; Professor is Shell-Deep in Turtles
Warm-blooded animals are able to control their body temperature. No matter what the temperature is outside, their internal body temperature remains the same. Only birds and mammals are warm-blooded. Birds rely upon their feathers to help adapt to temperature changes.: Ornithological Resources; Geographical Birding Guide (N.A.); Lincoln Park Zoo Birdlist; A Pigeon Inquiry; Banana-Pusher; American Birding
Mammals rely upon skin, hair, or fur to help adapt to temperature changes. Another characteristic of all mammals is the ability of the female to produce milk to feed her babies. Some mammals, like whales, live in the water and must adapt to changing water temperatures. Other land mammals, like wolves, have adapted to very cold climates. In general, however, warm-blooded animals must prepare for temperature extremes in order to survive.: Mammals; Lincoln Park Zoo - Mammals; Wild Wolves; What's So Bad About Bats?

Questions?
If you didn't find the answers to your classification questions, try searching Ask A Scientist.

Career Connections:
If you're interested in "Classification of Plants and Animals," consider one of these career possibilities: Botanist, Zoologist, Entomologist

Keywords and Cross-References:
adaptation (environment), adaptation (anatomy), amphibians, arachnid, arthropods, backbone, binomial, birds, butterfly (metamorphosis), butterfly (migration), carnivore, centipedes/millipedes, classification, cold-blooded, crustaceans, evolution, exoskeleton, fish, genus, herbivore, insects, invertebrates (earthworms), invertebrates (fruitfly), invertebrates (mealworms), mammals, mollusks, omnivore, phylogeny, plants, reproduction (earthworms), reproduction (flowering plants), reptiles, seeds, species, spider, spores, structure (plant anatomy), taxonomy, vascular, vertebrates (skulls), warm-blooded

Curriculum Connections:
Macmillan/McGraw-Hill:
Unit 10, Lesson 4
Unit 17, Lessons 3, 6
National Science Education Standards:
K-4 Life Science Content Standard C
K-4 Life Science Content Standard F
5-8 Life Science Content Standard C
K-4 Science as Inquiry Content Standard A
5-8 Science as Inquiry Content Standard A
Genetics