1. Strategies of Life

2.  Biology –branch of science dealing with living systems –How do we define life? What do all living things have in common? How do we describe life’s diversity? What is the basic unit of life?

3. Strategies of Life  All living organisms have the following characteristics

4. Strategies of Life 8 Characteristics of Life –ordered and complex –part of larger system of matter and energy –depends on chemical reactions –requires water –organisms grow and develop –regulate their use of energy and respond to environment –share genetic code –descend from common ancestor

5. Strategies of Life  Linnaeus  1700’s Swedish naturalist  developed the first classification system  The System included  Broadest categories are “kingdoms”  Only two kingdoms were recognized plants and animals  Now most biologists recognize five kingdoms

6. Strategies of Life  Five Kingdoms –Monera Bacteria –Protista Protozoans –Fungi Mold and mushrooms –Plants All plants –Animals All animals

7. Strategies of Life  Cells – The Basic Unit of Life –Single Cell Organisms Monera (NO nucleus) Protista –Multi Cell Organisms Fungi Plants Animals

8. Strategies of Life  Classification of organisms narrows Kingdom Phylum Class Order Family Genus Species

9. Strategies of Life  Scientific Name = Genus + species –Species is the narrowest category –For example: Human = Homo sapiens –Only the same species can produce offspring which are both viable and fertile

10. Strategies of Life  Human Classification  Kingdom – Animal  Phylum – Chordates  Subphylum – Vertebrates  Class – Mammals  Order – Primates  Family – Hominids  Genus – Homo  Species – sapiens (note: species begins with lower case)

11. Strategies of Life CategoryKatydidAnacondaGorillaHuman Kingdom Animal Phylum ArthropodChordate Class InsectReptileMammal Order OrthopieraSquamataPrimate Family TettigonlidaeBoidaePongidaeHominidae Genus ScudderiaEunectesGorillaHomo Species turcatamurinusgorillasapiens

12. Strategies of Life  Modern Classification of Organisms –Began in the 1950’s –Based on DNA –Comparison of genetic maps More closely related, more sequences in common Entire human genome now sequenced

13. Strategies of Life  How many different species are there?  1.4 million identified  3 – 30 million estimated  Which phylum is most successful in the number of species and total mass?  Arthropods  Which arthropods are most numerous?  Insects

14. Strategies of Life