3. Ecological Pyramids Graphical models of the quantitative
differences that exist between trophic levels of a single ecosystem.
They can be pyramids of numbers, biomass, or productivity.

4. the accumulation of substances, such as pesticides,
Ecology
Students will be able to:
-Define the term trophic level and identify and explain trophic levels in food chains and food webs.
-Explain the principles of pyramids or numbers, pyramids of biomass and pyramids of productivity, and construct such pyramids from given data. -Discuss how the pyramid structure affects the functioning of an ecosystem.
-Define the following population interactions and relate them to real world examples: neutralism, ammensalism, mutualism, commensalism, and parasitism.
Bioaccumulation =
the accumulation of substances,
such as pesticides,
or other organic chemicals
in an organism.

5. Population interactions occur in 5 main ways.
Interspecific competition
When members of two or more species
interact to gain access to the same limited resources.
Ex. Food, light, or space.
Predation
- occurs when a member of one species feeds directly on
all or part of a member of another species.
Parasitism
occurs when one organism feeds on the body of, or the energy is
used by, another organism, usually by living on or in the host.
Mutualism
is an interaction that benefits both species by providing
each with food, shelter, or some other resource.
Commensalism
an interaction that benefits one species but has little, or no, effect on the other.