Strategies of Life
Chapter 20
Great Idea:Living things use many different strategies to deal with the problems of acquiring and using
matter and energy
Chapter Outline
• The Organization of Living Things• What is Life• Classifying Living Things• Survival: A New Look at the Life
Around You• Strategies of Fungi• Strategies of Plants• Strategies of Animals
The Organization of Living Things
Ways of Thinking About Living Things
• Levels – Biosphere – Ecosystem – Community– Population– Organism– Anatomy &
physiology– Cellular– Molecular
• All levels complement each other
What Is Life?
The Characteristics of Life• High degree of order and
complexity• Part of larger systems of
matter and energy• Life depends on chemical
reactions in cells• Life requires liquid water• Organisms grow and develop• Regulate energy use• Share same genetic code, code
is heritable• All living things are descended
from a common ancestor
Classifying Living Things
Cataloging Life
• Linnaean classification– Shared
characteristics
• Hierarchy– Kingdom– Phylum– Class– Order– Family– Genus– Species
• Binomial nomenclature
Classifying Life cont.
• Kingdoms– Monera– Protista– Fungi– Plants– Animals
Classifying Human Beings
• Kingdom: Animals• Phylum: Chordates
– Subphylum: vertebrates• Class: Mammals• Order: Primates• Family: Hominid• Genus: Homo• Species: sapien
Implications of Linnaean Classification
• Use of DNA• Similarity depends on time and
change• Classification results from real events
Survival: A New Look at the Life Around You
Survival: A New Look at the Life Around You
• Autotrophs• Heterotrophs• Dealing with complexity• Two basic tasks
– Obtain and distribute molecules for energy
– Reproduce
Strategies of Fungi
Strategies of Fungi
• Growth– Filaments– Decomposers
• Structure– Mass of filaments
• Reproduction– Break filaments– Asexual reproduction
• spores
• Lichens– Two interdependent species
Strategies of Plants
The Simplest Plants
• Phylum: Bryophytes• Structure
– No roots– Photosynthetic
• Reproduction– Sexual – Asexual
Vascular Plants
• Phylum: vascular plants
• Structure– Roots, stems,
leaves– Control water loss
• Reproduction– Seedless– Gymnosperms– Angiosperms
• Sexual and asexual
Angiosperm
Strategies of Animals
Invertebrates
• Invertebrates– No backbone– Most diverse animals
• Arthropods– 70% of known animal
species
• Structure– exoskeleton
Vertebrates
• Organization– Ocean to terrestrial
• Evolution– Earliest fish– Bony Fish– Amphibians– Reptiles– Birds– Mammals