The Organization of Life

Defining and Ecosystem

• An ecosystem is all of the organisms living in an area together with their physical environment.

• Ecosystems do not have clear boundaries.

• Examples include a coral reef, an oak forest, a vacant lot, ect.

Components of an Ecosystem

• In order to survive ecosystems need five basic components:1. Energy (most often from the sun)2. Mineral nutrients3. Water 4. Oxygen5. And living organisms

• An ecosystem is made up of both living and nonliving things.

Biotic and Abiotic Factors

• Biotic factors are the living and once living parts of an ecosystem included all of the plants and animals.– Examples include dead organisms,

animals, and plants• Abiotic factors are the nonliving

part of the ecosystem.– Examples includes air, water, rocks,

sand, light and temperature.

Various levels of an Ecosystem

• Organism– Defined as an individual living

thing.– A species is a group of

organisms that are closely related and that can mate to produce fertile offspring.

– Examples include humans, trout, grizzly bears.

Various levels of an Ecosystem

• Population– Defined as all the members of

the same species that live in the same place at the same time.

– Important characteristic is that its members usually breed with one another rather than with members of other populations.

– Examples include a pack of wolves and a field of daisies.

Lets Review a Little:Various levels of an

Ecosystem• Communities– Defined as a group of various

species that live in the same place and interact with each other.

– The most obvious difference between communities is the types of species they have.

– Examples include a pond community and a pine tree community.

Habitat

• The place an organisms lives is called its habitat.

• Every habitat has specific characteristics that the organisms that live there need to survive.

• Organisms are not well suited for living outside of their habitat.

Evolution by Natural Selection

• Charles Darwin proposed the idea of natural selection, in which those organisms with a desirable trait tend to pass on those traits more frequently than those organisms without the trait.

• Darwin proposed that over many generations natural selection causes the characteristics of populations to change.

• A change in genetic characteristics of a population from one generation to the next is known as evolution.

• An adaptation is an inherited trait that increases an organism’s chance of survival and reproduction in a certain environment.

Evolution by Artificial Selection

• Many populations of plants and animals do not live in the wild but instead are cared for by humans.

• People control how these plants and animals reproduce and evolve.

• The selective breeding of organisms by humans for specific characteristics is called artificial selection.

Evolution of Resistance• Sometimes humans cause

populations of organisms to evolve unwanted adaptations bringing about resistance.

• Resistance is the ability of one or more organisms to tolerate a particular chemical designed to kill it.

• Several forms of resistance including pesticide resistance and drug resistance.

Now for the New StuffThe Diversity of

Living Things

• Most scientists classify organisms into six kingdoms based on different characteristics.

• Others classify using 5 placing all bacteria into the kingdom Monera.

Construct a foldable for the Classification of living things. Use the instructions provided at your table to complete it.

Archaebacteria

• Single celled• Lack cell nucleus• Reproduce by dividing in half• Found in harsh environments• Heterotrophic: absorption• Archae means ancient

Halobacteria – found in salty water conditions

Eubacteria

• Single celled• Lack cell nuclei• Reproduce by dividing in half

(asexual)• Incredibly common

E. Coli

Fungi• Absorb their food through their

body surface• Have cell walls that allow them

to stand upright• Have no chlorophyll• Most live on land

Fly Agaric Mushroom – very poisonous

Protists

• Most single celled but some have many cells

• Eukaryotic• Live in water environments• Some go through photosynthesis while

others are consumers• Most reproduce asexually

Star Protists

Plants

• Have many cells• Make their own food by photosynthesis• Have cell walls• Have roots that tap resources

underground and leaves that intercept light and gases in the air.

• Leaves and roots are connected by vascular tissue

• Classified as angiosperm (flowering plant) or gymnosperm (plants whose seeds are not enclosed)

Gymnosperm

Angiosperm

Animals

• Have many cells• Have no cell walls• Ingest their food for energy• Live on land and in water• Mostly sexual reproduction

with few exceptions• Classified as invertebrates (no

backbone) or vertebrates (backbone)

Vertebrate

Invertebrate

Alternative to the 5/6 Kingdom Classification System

• Three Domains– Domain is a taxonomic category above the

kingdom level– 3 Basic groups: Two prokaryotes and 1 eukaryotes• Domain 1= Bacteria• Domain 2= Archaea• Domain 3= Eukaryotes