Strategies of Life
Strategies of Life
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?
Strategies of Life
All living organisms have the following characteristics
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
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
Strategies of Life
Five Kingdoms– Monera
• Bacteria
– Protista • Protozoans
– Fungi• Mold and mushrooms
– Plants • All plants
– Animals• All animals
Strategies of Life
Cells – The Basic Unit of Life
– Single Cell Organisms• Monera (NO nucleus)• Protista
– Multi Cell Organisms• Fungi• Plants• Animals
Strategies of Life
Classification of organisms narrows
KingdomPhylum
ClassOrderFamilyGenusSpecies
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
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)
Strategies of Life
Category Katydid Anaconda Gorilla Human
Kingdom Animal Animal Animal Animal
Phylum Arthropod Chordate Chordate Chordate
Class Insect Reptile Mammal Mammal
Order Orthopiera Squamata Primate Primate
Family Tettigonlidae Boidae Pongidae Hominidae
Genus Scudderia Eunectes Gorilla Homo
Species turcata murinus gorilla sapiens
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
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
Strategies of Life
Species Distibution
Insects 53%
Other animals
20%
Higher plants 18%
Protozoa 2%
Fungi 5%
Algae 2%
Monera 0%
Species Distibution
Insects 53%
Other animals
20%
Higher plants 18%
Protozoa 2%
Fungi 5%
Algae 2%
Monera 0%