Ch 2 Principles of Ecology
2-1 Organisms and Their Environment
A. What is Ecology? – the ________ ____ interactions among __________________ and their
__________________. Ecologists use _____________________ and _____________________ observations to determine relationships between the ________________ and _______________ factors in an ecosystem.
1. _____________ ______________ – the nonliving parts of an organism’s environment
Ex: water, minerals, weather, sunlight…
2. _____________ _____________ – All the living organisms that inhabit an environment
Ex: Bacteria, Protists, Fungi, Plants, and Animals
B. Aspects of Ecological study – living things can be found in the _________, _________, and both fresh and salt _________. This thin layer where life can be found is called the biosphere.
C. Levels of Organization – Scientists cannot explain how life originated. Science can observe
____________________, which states: life comes from life. So how is life ____________________ ?
The part of the earth where _______ can be __________. Ex: any ecosystem
Composed of the
__________________ among the
____________________ in a community and the
____________factors. Ex: bacteria, fungi, plants, animals, weather, water, temperature...
A collection of
____________________ populations
Ex: bacteria, fungi, plants and animals
A group of organisms of the same
__________ that
____________________ and live in the same time and __________
____________________ living thing
____________________,
____________________ and organ systems

The ________ unit of life. All living things contain ____ or ________ cells and all cells come from ______existing cells
Amoeba Cheek cells
________ of atoms bonded together.
Bonds can be ________ (charge bond) or _________ (sharing electrons). Ex: H
2
O
The Periodic Table of Elements.
Each ________________of an atom contains ________________(+) and
_______________(neutral).
_____________ (-) orbit the nucleus.
D. Organisms in Ecosystems
1. ____________________ – the ____________________ where an organism lives out its life.
Ex: an earthworm feeds on organic material from the soil it moves through
2. ____________________ – the ____________________ and position a species has in its environment. Ex: The earthworm’s role is to decompose, recycle nutrients and be part of the food chain.
3. Living relationships
a). ____________________ – means living together
b). _________________________- a relationship in which one species
____________________ and the other is ____________________ harmed nor benefited. Ex: birds that live near grazing animals such as cows . Cowbirds benefit from the insects that are disturbed by the grazing and the cows are neither harmed nor benefited
c). _________________________- a relationship in which __________ species
____________________. Ex: Ants and the acacia tree. Ants protect the tree by attacking any animal that tries to feed on it. The tree provides nectar and a home for the ants.
d). _________________________- a relationship in which one species benefits at the
____________________ of another. Ex: a tick or leech attaches to its host. The parasite leaches nutrients from the host.

2-2 Nutrition and Energy Flow
Ch 2 Principles of Ecology cont…
A. How Organisms Obtain Energy
1. ________________ (producer)- means “self-feeder”
Ex: plants
2. ________________ (consumer)- feeds off of other organisms
Ex: animals
3. ________________ - eat animals that have already died
4. ________________ - break down and absorb nutrients from dead organisms
B. Matter and Energy Flow in Ecosystems
1. ________________ ________________ (pathways for matter and energy)- shows how matter and energy flow through an ecosystem
Ex: algae fish heron
2. ________________ ________________ – expresses all the possible feeding relationships
Bear Owl
Grouse
Seeds
Deer
Berries
Chipmunk
Grass fruit
Carnivore Omnivore Word origion
Consumer food
Herbivore
3. Trophic level – “feeding step”
-Only 10% of food energy is passed from
Step to step
C. Cycles in Nature
1. The water cycle

2. The carbon cycle
3. The nitrogen cycle
4. The Phosphorus cycle