Environmental ScienceChapter 4:

The Organization of Life

The Organization of Life Big Ideas

• In an ecosystem, the biotic and abiotic components interact to form an interconnected system.

• Species adapt to their environment through the process of evolution by natural selection.

• Humans classify the diversity of life on Earth in order to better understand their relationships.

Section 1: Ecosystems

GOALS• Distinguish between biotic and abiotic factors

in an ecosystem• Describe how a population differs from a

species• Explain the importance of habitats

What is Ecology?

The study of interactions

among organisms and

between organisms and

their environment.

Defining an ecosystem• Ecosystem: all the

organisms living in an area together with their physical environment

• Forest Ecosystem• Pond Ecosystem• Vacant Lot Ecosystem• Desert Ecosystem

All Ecosystems are connectedHow does your ecosystem impact the Atlantic Ocean?

Parts of an ecosystem

Parts of an ecosystem

In order for an ecosystem to survive it needs five basic components:

• Energy• Mineral Nutrients• Water• Oxygen• Living Organisms

What are some parts of this ecosystem?

If your are conducting a study of the interactions of vegetation,

animals, mineral composition of the soil, and water levels in a

saltmarsh. You are studying the saltmarsh ___.

ECOSYSTEM

Biotic and Abiotic FactorsBiotic: living & once living

parts of an ecosystem• Plants, animals, bacteria,

dead organisms, wastesAbiotic: nonliving parts of

an ecosystem• Air, water, soil, sunlight,

temperature

What are some biotic AND abiotic parts of this ecosystem?

Organizing Biotic Parts

Smallest UnitOrganism: an individual

living thing like you, a tree, a fox, a rose

Species: groups of closely related organisms that can mate & produce fertile offspring like red foxes or black widow spiders, or grizzly bears

Species Species: groups of

organisms that resemble each other in appearance, behavior, chemistry and genetic makeup…able to reproduce

• 3.6 to 100 million species (1.4 identified)

• Mostly insects/micro• Tropical forests

Known species1,412,000

Insects751,000

Plants248,400

PopulationPopulation: all the members

of the same species that live in the same place at the same time– Field mice living in a corn field,

grizzly bears of Yellowstone Park

– Members breed with one another, rather than with other populations

Community

Community: a group of various species that live in the same place and interact with each other –Pond Community–Pineland Forest

Community

Giraffes, lions, zebras, hyenas, and all the other living things of the

Serengeti make up a(n) ___

COMMUNITY

HabitatHabitat: the place

where an organism lives –Organisms are well

suited for their habitat

Habitat• Habitats provide an

organism with resources—anything an organism needs to survive and reproduce, including food, shelter, and mates

Biosphere

• All parts of the Earth where life is found

Section 1 Review• Biotic are living factors in an ecosystem• Abiotic are non-living factors in an ecosystem• Biosphere is composed of ecosystems,

ecosystems are composed of communities, community is made up of populations, populations are composed of species, species are composed of individuals

• Habitats provide organisms with the resources they need to survive

Section 2: Evolution

GOALS• Explain the process of evolution by natural

selection• Explain the concept of adaptation• Describe the process of resistance

Change is one thing that is

certain in life.

Change occurs in many ways

-cultures change-individuals

change-species change

Essential Question:

You’ve read about the diversity of living

organisms on Earth (plants, animals, protists,

fungi, bacteria)

How did they get here?

Change in the genetic

characteristics of a population

over time!

What is Evolution?

- biologists say that the environment exerts a strong influence over which individuals survive to produce offspring- the best suited (most fit) organisms survive and reproduce- individuals with certain traits are more likely to survive and reproduce

Natural Selectionaka

“Survival of the Fittest”

- the unequal survival and reproduction that results from the presence or absence of particular traits

Evolution by Natural Selection

1-Organisms produce more offspring than can survive2-The environment is hostile and contains limited resources3-Organisms differ in the traits they have4-Some inherited traits provide organisms with an advantage (ADAPTATION)5-Each generation contains proportionately more organisms with advantageous traits

Coevolution

Process of 2 species evolving in response to long term interactions with each other

If natural selection concludes that all dogs are closely related through a common ancestor, then how come this

Chihuahua and this Great Dane are so different?

Question:

Artificial Selection:Artificial selection refers to the process where humans select organisms with certain traits to

breed.

Resistance:Resistance occurs when humans expose

organisms to certain conditions/chemicals, and those organisms become tolerant or “immune”

to the conditions over time. Examples: A. Insects can become resistant to pesticidesB. Bacteria can become resistance to

antibiotics

Section 2 Review• Evolution by natural selection is the

unequal survival and reproduction that results from the presence or absence of particular traits

• Adaptation increase an organism’s chance of survival and reproduction in a certain environment

• Resistance is the ability of an organism to tolerate a particular chemical or condition designed to kill it

Question: What is your favorite organism(s) of all time? Why?

This cat’s favorite organism is a frog.

Section 3: The Diversity of Living Things

GOALS• Name the five kingdoms of organization and identify

characteristics of each• Explain why bacteria and fungi are important• Describe the importance of protists in the ocean

environment• Describe the interdependence of angiosperms and

animals• Explain why insect animals are so successful

Bacteria:-single-cell, no nucleus-cell wall-reproduce by division-two types • Archaebacteria (extremophiles)• Eubacteria

-most diverse & commonorganisms on Earth-many important roles

decomposers, recyclers, assist in digestion

Examples?- E. coli, cyanobacteria

Airborne Bacteria Lab-Bacteria are so important, that humans (and many other organisms) would be extinct without them.

-The point of this lab is to review the scientific method, and gain an appreciation for how much bacteria we are surrounds by.

Fungi:-single cell, nucleus, cell wall, no chlorophyll

-absorb food from around them

- decomposers: feed on dead organisms

- Examples? Athlete’s foot, cheese, yeast

Protists:-many single-celled

-very diverse, most live in water

-important role (algae/phytoplankton)?

Examples?

Diatoms, dinoflagellates, amoeba, paramecium, amoeba, kelp

Plants:-many cells, cell wall-photosynthesize-most land dwellers-supply oxygen and food to much of the world-gymnosperms (conifers) -woody plants -seeds not enclosed in fruits-angiosperms (flowers/fruits) -flowering plants -produce seeds in fruit-important role?Most land animals depend on flowering

plants for food

Animals:-many cells-no cell wall-must take in food-live on land or water

Animal Types:-Invertebrates-no backbone

-Vertebrates-have backbone

Insect Success:

-waterproof external skeleton-move quickly-reproduce quickly-most can fly-small size -little food needed -hide

-insects & plants coevolved -pollination -eat plant pests

Section 3: Review

• The five kingdoms are bacteria, fungi, protists, plants, animals

• Bacteria and fungi are decomposers, recyclers and help release nutrients

• Protists in the ocean are the primary source of food• Most animals rely on angiosperms for food• Insect animals are so successful because of their

exoskeleton, size, agility, capacity to fly and hide

The Organization of Life Big Ideas

• In an ecosystem, the biotic and abiotic components interact to form an interconnected system.

• Species adapt to their environment through the process of evolution by natural selection.

• Humans classify the diversity of life on Earth in order to better understand their relationships.