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