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
Parts of an ecosystem
In order for an ecosystem to survive it needs five basic components:
• Energy• Mineral Nutrients• Water• Oxygen• Living Organisms
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
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
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
Habitat• Habitats provide an
organism with resources—anything an organism needs to survive and reproduce, including food, shelter, and mates
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?
- 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
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
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.