( At any one time in history, there are millions ofd'ifferent kinds of plants and animals in the world. In1753, a scientist in Sweden named Caro1us Linnaeusthought of an orderly system for classifying plants andanima1s. He grouped all organisms according to a two-part name (binomial). 'I'he 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 is much morecomplicated having many levels of hierarchical organization. For examp1e, taxonomicsystems group organisms according tcC1ítructure and physiologlca I connectlOrl§=::,between organisms. Phylogcnic systems classify based on ~netic connectiori$:Evolution theories have impacted modern classification.

?",.. In order to begin to classify plants, consider the structure by which the planta sorbs wate. Plants are either ~lar or non-vascular. Vascular plants have tube-1 e cures that transport water from the roots to th~ stern to the leaves. Non-

vascular plants absorb water only throu h their surfaces. Another way to considerplant classification is according to e roductiüji)Some plants reproduce by producingseeds. Others produce spores .

-'l 1'0 begin to classify animals, consider theC~~le. Animals that have a. . () backbone are called vertebrates. Animals that do not have a backbone are called

~~ G invertebrates./. ---- -

\f~~$ iYl.·v~h-r~ J-\ A11invertebrates lack backbones, but their other physical characteristics are/ \ quite varied. They must be, considering that 95 percent of a11 animals are

S~ i"'D"'-1"'invertebrates. Some, like worms, have soft bodies with no bones at a11. Some other),..h"" invertebrates, like snails, have soft bodies, but carry a hard shell for protection. 'I'hese

soft-bodied invertebrates that live in water or on land are grouped as mo11usks.Besides snails, some other rnollusks are clams, mussels, and squid.

~'""' Some other invertebrates have tough coatings en the outside of their bodies

(exoskeletoris), jointed 1egs, and a segmented body. This group is known as the~(l"<~ arthropods. Insects, spiders (arachnids), centipedes/millipedes, and shrimp, lobster,../" '" ,-- .

~ ••.,,¡., ~and crabs (c;rustaceans) are all arthropods. There are more insects (over 900,000species) than any other group of arthropods. There are more arthropods than anyother group of invertebrates. And, considering that 95 percent of all animals areinvertebrates, that makes arthropods truly the most abundant group. One particularlypopular member of the insect world is the butterfly. 'I'his arthropod, with its toughouter shell, characteristic wings, and antennae, beIongs to the insect family.

lo AlI vertebrates have a backbone. Their other physical character~ are quitevaried. One way to consider groups of vertebrates is according to thei~ Animalsthat primarily eat plants are known as _herbiYDres. Animals that feed mostly on meatare known as carnivores. Some animals, called omnivores, eat both plants and meato

. ., An animal's eating habits are influenced by its anatomy. Meat-eaters have jaws ~and teeth designed for tearing and crushing. 'I'he canine teeth are enlarged and the ~

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CLASSIFICATION OF PLANTS & ANIMALS

P•..,ants

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~n,I~T"", have sharp cusps. The intestinal tract is adapted for handling quick digestion-::::::ea . Plant-eaters usually have large incisors for cropping and cutting plants. Theirarge. ridged molars are adapted for grinding tough plant fibers and their intestines-~ rather long, allowing for slow digestion of plant fibers .

. nother way to consider groups of vertebrates is according to their body---~--~-e perature All vertebrates are either cold-blooded 01' warm-blooded. A vertebrate isco idere cold-blooded if its internaÍ body temperature matches the external.emperature around it. Fish, amphibians and reptiles are examples of cold-blooded

animals. Their dependence on the water 01' land makes it necessary for them to adaptID the temperature surrounding them.

q Warm-blooded animals are able to control their body temperature. No matterwh,Ú the temperature is outside, their internal body temperature remains the same.Only birds and mammals are warrn-blooded. Birds rely upon their feathers to helpadapt to temperature changes. Mammals rely upon skin, hair, or fur to help adapt totemperature changes. Another characteristic of all mammals is the ability of thefemale to produce milk to feed her babies. Some mammals like whales, live in thewater and must adapt to changing water temperatures. Other land mammals, likewolves, have adapted to very cold climates. In general, however, warm-bloodedanimals must prepare for temperature extremes in order to survive.

ExercisesGeneral comprehension.From the information given in the text complete the following.

1. Mention the criteria used by Linnaeus for classifying plants and animals.

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2. Identify the criteria used for classifying plants described in paragraph 2.~W~-~~~~ ~~f"C-?

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3. Based on the information written in paragraph 3 draw a graphic organizer toshow how animals are classified. Give examples.

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