First Unit: Ecology

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First Unit Ecology

• The World Around Us

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Biology is the study of LIFE

• There is no one all-inclusive definition of life.
  Instead, biologists describe life by describing
  characteristics of living organisms.

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• BUT WHAT ABOUT SAMMY???

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Characteristics include

• Metabolism the sum total of all the chemical
  reactions that occur in living organisms

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• Nutrition (autotrophic and heterotrophic) how
  an organism obtains materials necessary for
  growth, energy, repair, maintenance
• autotrophicself feeders (plants)
• heterotrophicneed to take food in (animals)

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• Digestion (ingestion, digestion, absorption,
  egestion) breaking down food into a usable form

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• Transport movement of materials within an
  organism

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• Synthesis ability to combine smaller molecules
  into larger molecules

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• Growth and development increase in size and
  number of cells, change from immature to the
  mature form

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• Excretion ridding the body of metabolic wastes

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• Regulation control and coordination of all life
  activities

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• Locomotion ability to move from place to place

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• Organisms have the ability to maintain
  HOMEOSTASIS, which is a state of internal
  regulation and balance. They do this by way of
  DYNAMIC EQUILIBRIUM, a way of constantly checking
  and altering internal systems in order to
  maintain homeostasis. If these systems are
  disrupted, the organism is open to disease

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TWO MORE PROCESSES

• Respiration the way an organism makes the
  energy they need to survive

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• Reproduction making more of a specific
  speciesthe only process not necessary for EVERY
  member of the species to do

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Levels of organization

• Atoms? Molecules ? Organelles ? Cells ? Tissues ?
  Organs ? Organ Systems ? Organisms ? Population ?
  Community ? Ecosystem ? Biomes ? Biosphere

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Ecology

• The study of the relationships between organisms
  and between organisms and their environment

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Requirements of an ecosystem

• There must be a constant flow of energy into the
  ecosystem and there must be organisms that can
  use this energy to make organic compounds

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• 2. There must be a cycling of materials between
  the living organisms and the environment

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Biotic vs. Abiotic Factors

• Biotic factors these are all the living
  elements of an ecosystemplants, animals,
  bacteria, fungi, etc.
• Abiotic factors these are all the parts of an
  ecosystem that have not nor ever will be alive.
  Examples light intensity, pH, soil type,
  availability of minerals, amount of water,
  temperature

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• ABIOTIC FACTORS are also called LIMITING FACTORS.
  They determine which plants can live in an area,
  and plants in turn determine which animals can
  survive in an area.
• (welcome to the land of biology, where many words
  overlap in their meaning!!)

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Types of interactions in an ecosystem

• Nutritional relationships involve the transfer
  of nutrients from one organism to another
• autotrophsmake their own food. Also called
  producers (plants/algae)

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• Heterotrophscannot make their own food and
  therefore must ingest their food. This includes
  all of the following categories

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• c. Saprophytes/saprobesobtain their nutrients
  from the remnants of other organisms. Fungus,
  Bacteria, Invertebrates (the FBI)

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• d.Herbivores--animals that feed exclusively on
  plant material (cow, deer)

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• e.Carnivoresanimals that feed exclusively on
  other animals
• Predators catch, kill, and consume their food
• Scavengers feed on the remains of animals that
  they have not killed

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• f. omnivorefeeds on both plant and animal
  material

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Symbiotic Relationships

• Where different species of organisms live
  together in close association

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1. Commensalism

• One organism benefits, one is not affected
• Barnacles on whales

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2. Mutualism

• Both organism benefit
• Lichen (algae and fungus together)

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Parasitism

• One organism benefits, the other is harmed
• Parasite lives on a host
• Tapeworms, mosquitoes, fleas

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Energy flow relationships

• In order for an ecosystem to be self-sustaining,
  there must be a flow of energy between organisms
• This flow is visualized in the following ways

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1. Food Chains

• Series of organisms
• through which food
• energy is passed

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• PRODUCER is always the first stage of a food
  chain. It will be an autotroph (green plant)
• All other steps are consumers (heterotrophs)
• Primary consumer must be herbivore/omnivore,
  secondary must be onmivore/carnivore

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• DECOMPOSERS are always part of a food chain but
  almost never included. They can interfere with
  any stage of a food chain as they break down dead
  organisms and return the nutrients to the soil.

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2. Food Web

• A series of interconnected food chain
• Shows a truer
• picture of the
• relationship between
• organisms

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3. Pyramid of energy

• Greatest amount of
• energy is always in the
• producer level
• Only about 10
• is passed to each
• new level

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4. Pyramid of biomass

• Less energy at each
• level means that less
• organic matter
• (biomass) can be at
• each level

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Cycles of Materials

• A major rule of a self-sustaining ecosystem
• is that various materials must be recycled
• between organisms and the abiotic
• environment

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Carbon-Hydrogen-Oxygen Cycle
GLUCOSE
OXYGEN
PHOTOSYNTHESIS
AEROBIC RESPIRATION
WATER
CARBON DIOXIDE
DECAY
BURNING
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Water Cycle
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The Nitrogen Cycle

• Nitrogen is necessary for
• proteins and DNA
• Involves decomposers
• Many legume plants

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Ecosystem Formation

• This is when the environment undergoes a severe
  environmental catastrophe that results in the
  ecosystem reverting to a more primitive status.
  When left alone again, it goes through a series
  of changes. Given enough time, these changes
  will lead to another stable environment that will
  remain until another catastrophe occurs.

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Ecological Succession

• Pioneer organisms the first plants to populate
  a given areaoften lichen

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Ecological succession, continued

• The pioneer organisms help to make an area
  healthy enough to support other life forms. PO
  are often followed by grasses, shrubs, conifers
  (cone-bearing trees), and deciduous
  (leaf-bearing) trees

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Ecological Succession, cont

• A CLIMAX COMMUNITY is the last community that
  will develop and this is the collection of plants
  and animals that will exist in an area until
  another catastrophe occurs. A CC is
  stable and long lastingand
  the CC defines what the biome
  is.

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Abiotic Factors

• are the primary factors in controlling which
  plants and, therefore, which animals will be in
  an ecosystem. These factors also regulate the
  CARRYING CAPACITY of an area, which is the number
  of members of a species that an area can support.
  

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Competition

• While the environment is being re-established,
  COMPETITION occurs. This is the struggle between
  different species for the same limited resources.
  The best adapted species will win and survive,
  while the other will not flourish, and perhaps
  die out.
• ONLY ONE SPECIES CAN EXIST PER NICHE
• Example grey squirrels and red squirrels

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Biodiversity

• To help an ecosystem stay healthy, it should have
  a high level of biodiversitythis is a measure of
  the number of different species located in one
  area. The greater the biodiversity, the more
  stable of an ecosystem.

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Niche

• This is the role an organism plays. The niche
  includes habitat, reproductive habits, food
  choices, hunting strategies, interactions with
  other species.

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Habitat

• The area where an animal lives is called its
  habitat. Habitats are specific to each species,
  but species habitats can overlap.

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BIOMES

• Once a climax community is established, the biome
  can be determined. Biomes are large geographical
  areas that have similar plant life and abiotic
  factors.

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Tundra

• Permanently frozen subsoil
• Lichen, moss, caribou
• Cold, cold, cold!
• North Pole

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Taiga

• Long, severe winters
• Conifers, moose, black bear
• Siberia, northern
• Canada

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Temperate Deciduous Forest

• Deciduous trees, cold winter, warm summer
• Squirrel, fox, deer
• Northeast USA

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Tropical Forest

• Heavy rainfall, warm temperatures, broad-leaved
  plants
• Monkeys, leopards, toucan
• Brazil

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Grassland

• Also known as plains,savannah
• Grasses, buffalo, prairie dogs
• The America
• mid-west, African
• plains

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Desert

• Sparse rainfall, extreme temperature fluctuations
• Cactus, drought resistant
• shrubs, lizards
• American southwest

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Terrestrial Biomes

• are determined
• by altitude and
• latitude.

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Aquatic biomes,

• the most important being the OCEANS, are
  extremely stable.
• Characteristics
• Most stable environment
• Absorbs and holds vast amounts of solar heat
• Contains a supply of nutrients and dissolved salts

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Aquatic Biomes, cont

• Habitat for a large number of species
• Most of the photosynthesis on earth occurs
  in the ocean
• Freshwater biomes (lakes, rivers) often undergo
  succession towards a terrestrial community

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Humans and the Biosphere

• Humans are the only organisms on the planet who
  have such an extreme capacity to change their
  environment

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Negative Aspects

• Extinction
• Importing invasive organisms (zebra mussels,
  purple loosestrife)
• Wildlife exploitation
• Poor land management
• Urbanization
• Pollution (fossil fuels, acid rain, trash)
• Biomagnification
• ALL CAUSED BY OVERPOPULATION!!

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Positive Aspects

• Population controls
• Conservation of resources
• Pollution controls
• Species preservation
• Biological controls
• Learning from our mistakes and fixing them

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Changes for the future

• Authors (Rachel Carson, Thoreau, Abby)
• Visionaries (Leopold, Muir, Roosevelt, Edward O.
  Wilson)
• Organizations (ADK, Sierra Club)
• Recycled products and more efficient machines
  (hybrid vehicles)