Interdependence within Environmental Systems
04.30.15

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Describe how events and processes that occur during ecological succession can change populations and species diversity

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Succession : some of the organisms in an area are gradually replaced over time by new species
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Pioneer species: those that first colonize bare soil or rock; examples—lichen and mosses
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Climax community: mature ecosystem that develops through stages and remains until abiotic factors change; high species diversity

Primary Succession
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Starts from region where there is no preexisting community
Volcano or flood
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Simple structure
Broad niches
Low species diversity
Secondary Succession
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Occurs where an existing community has been cleared by a disturbance
Tornadoes, forest fires, mudslides
Happens faster than primary succession

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Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms
Symbiosis is a relationship in nature where two organisms live very closely together

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Parasitism
A symbiotic relationship in which one organism lives in or on another organism (the host) and harms it to gain food.
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Examples:
Mosquitoes biting animals
Mistletoe (plant parasite)
Mutualism
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A symbiotic relationship in which both organisms benefit from the relationship
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Examples:
Birds called oxpeckers eat the insects off of large herbivores like cape buffalo

Commensalism Competition
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A symbiotic relationship in which one organism benefits and the other is unaffected
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Example:
Barnacles on a whale
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Individuals compete for resources such as food, space, and mates
Can be between different species or between individuals of the same species

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A lichen is a combination of two organisms, an alga and a fungus. The fungus gets its food from the alga while the alga gets water from the fungus. This is an example of which relationship? Explain.

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Describe how environmental change can impact ecosystem stability

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Human impact on the natural world has increased dramatically as the scope and intensity of human activities have increased. Unresolved problems include:
Loss of biodiversity—current extinction rates are 100 to 1000 times higher than prehuman levels
Desertification —the change of usable land into desert caused by poor land management
Food production—over 1 billion people remain undernourished
Overfishing
Deforestation— clearing of forests for agriculture, lumber, etc.

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Water pollution
Oil pollution
Inorganic pollutants—mercury, lead, road salt, acid drainage
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Greenhouse effect—natural atmospheric warming caused by gases such as CO2 in the atmosphere
Bioaccumulation– occurs when highly persistent pesticides are stored in the body
This increases as you go UP the trophic levels of a food chain

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Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

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Organisms on Earth are
Carbon based so Carbon is essential for life .
Producers take Carbon from the atmosphere and through photosynthesis make it usable to the rest of the biotic community
Carbon is returned back to the atmosphere as animals exhale during respiration

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Nitrogen is mostly found in an unusable form.
Bacteria are the only organisms that can break down Nitrogen into a usable form
Nitrogen-fixing bacteria make
Nitrogen available in the soil.
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Nitrogen is an important part of:
DNA (base pairs)
Protein (amino acids)

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The diagram shows several phases of the Nitrogen cycle.
Why do living organisms depend on the nitrogen cycle?
What is the role of bacteria in this cycle?

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Compare variations and adaptations of organisms in different ecosystems

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An adaptation is an inherited feature of an organism that enables in to survive and reproduce in its habitat
They are the end result of the evolutionary changes that a species has gone through over time
(evolution does NOT happen over night!)
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Adaptations may be:
Behavioral
Physiological
Structural (morphological)

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Activity patterns, e.g. nocturnal behavior
Movement
Defense of resources
Predator avoidance
Reproduction feeding

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Many plant adaptations are concerned with maintaining water balance

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Animals exhibit a great diversity of adaptations. These enable them to live within the constraints of their particular environment
Example: Rabbits

1.
Which of the following characteristics could help short plants survive in areas with limited sunlight a. Broad leaf surfaces b. Brightly colored flowers c. Thick stems d. Shallow roots
2.
Give three ways in which a polar bear is adapted to its environment:

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Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

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Food chain: a path of energy through the trophic levels of an ecosystem
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Food web: a diagram that shows the feeding relationships between organisms in an ecosystem
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Omnivores: organisms that eat both plants and other organisms
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Decomposers: An organism who recycles nutrients by feeding on dead or decaying organisms.

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As you go up each trophic level energy is lost
Most energy is lost to the environment as heat
An organism stores about 10% of the energy stored by an organism in the level below it

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Recognize that long-term survival of species is dependent on changing resources that are limited

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Investigate and analyze how organisms, populations, and communities respond to external factors

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Population: a group of individuals of the same species inhabiting the same area
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Community: populations of different species that live in the same place
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Ecosystem: contains all the abiotic(non-living) and biotic(living) factors
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Carrying capacity: the maximum population size that an environment can support

Random Distribution
The position of each individual is independent of the others
Uniform Distribution
Individuals are evenly spaced
Clumped Distribution
Individuals are clustered together in groups; most common

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Exponential Growth Logistic Growth
Rapid population growth
Produces a J-shaped curve
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Population growth increase slows to a level that can be supported by the environment
Produces S-shaped curve

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Limiting factors: any factor that limits the size of a population
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Density-Dependent Factors -depends on population size
Competition, predation, disease
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Density-Independent Factors -doesn’t depend on population size
Temperature, rainfall, natural disasters

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Summarize the role of microorganisms in both maintaining and disrupting the health of both organisms and ecosystems

Viruses
Very small
NOT A CELL
NO
Invades host and makes copies
None
Vaccines, good hygeine
None
Chickenpox, AIDS
Verses size
Type of cell
Living?
Reproduction
Treatment
Prevention
Benefits
Example
Picture
Bacteria small prokaryote yes
Binary fission antibiotics
Vaccines, good hygeine
Helps with digestion
E. coli, anthrax

Example Question