Download Ecology Notes Levels of Organization/Food Chains and Food Webs

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Ecology Notes
Levels of Organization/Food Chains and Food Webs
Ecology definition:
-Eco: from Greek oikos, meaning “house”
I. Levels of Organization from the most general to most specific
A. __________________: An individual member of a species. A member of a species must
be able to mate and produce fertile offspring.
B. _____________: A group of the same species living in the same area.
C. _________________________: A group of different species that live together in one area.
D. _________________________: All of the organisms (biotic factors) as well as the climate,
soil, water, rocks and other nonliving things (abiotic factors) in a given area.
E. _____: A major regional or global community of organisms, usually characterized by
the climate conditions and plant communities of the region
F. ________________________: All of Earth including its atmosphere
II. Energy in an Ecosystem: Food Chains, Food Webs, and Food Pyramids
A. Definitions:
1. ____________________: the place in which an organism lives ex: a deer lives in a
______________
2. ___________________: an organism’s role in the food chain ex: a deer is a
______________ ______________ (herbivore) because it feeds upon plants
B. Types of Niches
1. ________________________________ (Producers)
a. ______________________: can photosynthesize and produce food using energy
from the sun ex: plants and some protists
b. ______________________: can produce food from inorganic
Chemicals in the environment ex: some bacteria
2. ________________________(Consumers: eat other organisms)
a. ______________________: eat plants ex: _________________
b. ______________________: eat meat ex: __________________
c. ______________________: eat plants and animals ex: _____
d. ___________: eat animals that are all ready dead (carrion)
Ex: ___________________________
e. _________________: breakdown dead organisms and return
Their nutrients to the soil ex: _______________and __________
C. Types of Heterotrophs in a Food Chain/Food Web
1. ____________ _______________ (1st level consumers): feed upon
Plants (herbivores)
2. ___________ ________________ (2nd level consumers): feed upon
Primary consumers
3. ____________ _______________ (3rd level consumers): feed upon
Secondary consumers
4. ____________ _______________ (4th level consumers): feed upon
Tertiary consumers
D. Types of Symbiosis
When two organisms live in close contact, they form a symbiotic relationship.
• ________________: both organisms benefit.
Example: Bacteria on the roots of some plants provide the plant with nitrogen to
make proteins, and the plant provides the bacteria with a place to live.
_____________________: one organism benefits and the other is neither harmed nor
benefitted
• Example: Barnacles on a Whale Barnacles are sessile, filter-feeders. They will starve
if they are in polluted water. If they attach to whales, the whales will bring them to
unpolluted water to feed. The whales are not harmed nor helped by
the relationship.
• _______________________: one organism benefits while the other is harmed
•
E. Mutualism Examples
• Example: Bacteria on the roots of some plants provide the plant with nitrogen to
make proteins, and the plant provides the bacteria with a place to live.
• Crocodile opens wide for the plover because the plover likes to pick its teeth
clean of rotting meat. Free dental care, free meal.
F. Commensalism Examples
• ________________________ Barnacles are _______________, filter-feeders. They will
starve if they are in polluted water. If they attach to whales, the whales will bring
them to unpolluted water to feed. The whales are not harmed nor helped by
the relationship.
• The bird benefits from the shelter of the tree and the food supply that the tree
attracts. The tree is not harmed or helped by the bird.
G. Parasitism Examples
• ______________________ in the heart of a dog.
• Adult lice on human.
•
•
_______________________________ – two species share a requirement for a limited resource;
reduces fitness of one or both species
____________________________ – one species feeds on another; enhances fitness of
predator but reduces fitness of prey
H. Movement of Energy through a Food Chain/Food Web
1. _____________________________: Feeding position in a food chain
a. _______________ indicate the direction of energy flow through a food chain /
food web
b. Each ecosystem has its own unique trophic structure.
c. ______________________ are always at ____________________ because they
produce the food to start the exchange of energy through an ecosystem
•
Arrows indicate direction of energy flow
Trophic Level 4
Tertiary Consumers
Trophic Level 3
Secondary Consumers
Trophic Level 2
Trophic Level 1
Primary Consumers
Producers
Decomposers
2. _____________________________: _______________, linear diagram of energy flow
through an ecosystem
3. ______________ __________________ A more ___________________ diagram that
shows all of the various predator/prey relationships in an ecosystem
I.
______________________ __________________: shows the reduction in energy available at
each higher trophic level
1. ____________________must comprise ______________ of the mass of the biotic part of
the ecosystem * This is the only place where (solar) energy enters the ecosystem.
2. ___________________ is always ___________ in the form of _____________ so energy
transfers are only _______________% efficient at each trophic level. (90% of the energy is “lost”
as heat energy to the atmosphere at each level)
J. Pyramid of Numbers: Each higher trophic level decreases by 90% (only 10% remains)
K. Pyramid of Biomass:
1. _________________ form the broad base of the food pyramid because they have the
greatest biomass (________________) as primary producers that convert sunlight into food
through photosynthesis.
2. The second level represents the primary consumers, the herbivores that consume
plants. This second level has _____ ___________ than the base because almost 90% of the
energy consumed by herbivores is lost as __________________ or waste products that are
broken down by decomposers.