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The Principles of Biological Classification and ther Diversity of Organisms

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All organism within a group show certain common characteristics that have been used to place them in that group. Organisms have a large number of different characteristics, many of which enable them to survive in the ecosystem in which they live.

Why do we classify?

• So that organims can be recognised all over the world.

Genus - Many similarities. Can't interbreed
Species - Similar organisms. Can interbreed to produce fertile off-spring.

Binomial Nomenclature

• Binomial Nomenclature is a system of classifying organisms
• 'Binomial' means two names
• e.g Homo sapiends, Felis domesticus, Canis familiris
• The first word is the genus (always starts with a capital letter) and the second is the species (not capital letter), both are either italicised or underlined.

Dichotomous Identification Key (Be able to use and make one)

• Always make a table for answers

(Editors note: We may add an example at a later date.)

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Features of Vertebrates

• Animals with a backbone

Fish - Cold Blooded

• Covered in scales
• have gills
• have fins
• aquatic
• produce egs
• dont look after offspring

Amphibians - Cold Blooded

• soft skin (slimy)
• live on land, lay eggs in water
• young (aquatic, gills) Adult lungs (terrestrial)
• no parental care
• 4 limbs

Reptiles - Cold Blooded

• hard tough skin
• scales
• eggs have soft shells, layed on land
• have lungs
• no parental care (usually)

Birds - Warm Blooded

• feathers
• beak
• claws
• can fly with wings
• lay eggs - hard shell
• parental care
• lungs

Mammals - Warm Blooded

• hair
• external ears
• young develop inside. Live offspring
• parental care
• mammary glands
• land mammals have four (4) limbs

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You also have to know about Anthrapods. These are invertebrates

• segmented body (head, thorax, abdomen)
• exoskeleton
• jointed legs

Examples of:

Crustaceans - (shrimp, waterlouse)

• Many legs
• 2 pairs of antennae
• body coverd by shield

Arachnids (spiders, scorpion)

• 8 legs
• 2 body parts (head, abdomen)

Insects

• 2 sets of wings
• antennae
• 6 legs
• compund eyes
• 3 body parts (segments) head, thorax, abdomen

About the Author

by: Admin
Total views: 7551
Word Count: 1126
Date: Sun, 21 May 2006 Time: 12:00 AM
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