Unit 2: Interdependence
Guided Outline to take us through Unit 2: Interdependence. Will be completed with
assigned due dates using the textbook as a resource.
Food Webs Due: __________________
Interdependence: A Key Theme in Ecology: Section 18.1 (pages 359 – 362)
KEY POINTS: Describe examples of interdependence upon organisms in their
environment.
Why are animals interconnected with plants?
Plants produce the glucose animals use for cellular respiration, as well as the oxygen.
Animals then produce carbon dioxide for the plants to use in photosynthesis. When the
animals decompose, the plants can use their nutrients.
Discuss one example of interdependence using the forests of the Eastern portion of the
United States.
When a lot of acorns are produced by tress there will be a large population of deer and
mice (because they eat acorns). With a large population of deer comes a large population
of deer ticks. The deer ticks lead to Lyme’s disease in humans.
Explain the hierarchy of the different levels or organization (organism to biosphere)
Organism  Population  Community  Ecosystem  Biome  Bioshpere
1. Assuming wolves eat deer, how could a disease that kills a large portion of the
wolf population affect the mice population in a forest ecosystem?
The population of deer with increase and they will compete with the mice for food, so
there may be a decrease in the mice population.
2. Why is the amount of sunlight important to the animals in an ecosystem
Because it is the ultimate source of energy for an ecosystem.
Ecosystem Components: Section 18.2 (pages 363 – 365)
KEY POINTS: Compare abiotic and biotic factors
Describe two mechanisms that allow organisms to survive in a changing environment
Explain the concept of a niche
Biotic factors & example:
Living components of environment
Ex: trees, animals
Abiotic factors & example:
Non-living components of an environment
Ex: elevation, precipitation, nutrients in soil
Explain a tolerance curve
Organism performance vs. values of an environmental factor
What does a tolerance curve indicate about an organism?
The range in which an organism can function.
Acclimation & example: Process of adjusting tolerance to abiotic factors
Describe Conformers: do not regulate internal conditions
What type of organism do you think this is? Reptiles
Describe Regulators: do regulate internal conditions
What type of organism do you think this is? Humans
Describe Dormancy: state of reduced activity during unfavorable environmental
conditions
Describe Migration: movement to a more favorable habitat
Niche: specific role or way of life within an ecosystem
How does an organism’s habitat differ from its niche? Niche includes many more factors
than habitat
Generalist: species with broad niche
Find an example beyond your textbook:
Specialist: species with narrow niche
Find an example beyond your textbook:
3. Why do species never occupy exactly the same niche?
They would have to compete for limited resources
4. If some of the resources in a habitat are destroyed, which would be more likely to
survive, a generalist species of a specialist species? Explain.
Generalist because they can use multiple resources
5. A small rodent species and a bird species are adapted to cold temperatures. How
might each species survive a major temperature increase?
Rodent = dormancy
Bird = migration