2.1 Structure
Assessment Statements
 2.1.1 Distinguish between biotic and abiotic (physical)
components of an ecosystem.
 2.1.2 Define the term trophic level.
 2.1.3 Identify and explain trophic levels in food chains
and food webs selected from the local environment.
 2.1.4 Explain the principles of pyramids of numbers,
pyramids of biomass, and pyramids of productivity,
and construct such pyramids from given data.
 2.1.5 Discuss how the pyramid structure affects the
functioning of an ecosystem.
Assessment Statements
 2.1.6 Define the terms species, population, habitat,
niche, community, and ecosystem with reference to
local examples.
 2.1.7 Describe and explain population interactions
using examples of named species
2.1.1 Distinguish between biotic and abiotic
(physical) components of an ecosystem.
 Biotic – Living
components within an
ecosystem
 Plants, animals, etc.
 Abiotic – Non-living
factors of the ecosystem
(the environment)
 Soil, Water, etc.
2.1.2 Define the term trophic level.
 Trophic level – Feeding
level within a food chain.
Multiple food chains
make up food webs.
 Producer – Makes own
food
 Consumer – Consumes
other organisms for food
 Decomposer – Eat dead
biomass
2.1.3 Identify and explain trophic levels in food chains
and food webs selected from the local environment.
 For this we will be
drawing our own food
web. You will need to
make sure that you
distinguish the levels,
and can explain the
relationships.
2.1.4 Explain the principles of pyramids of numbers, pyramids of
biomass, and pyramids of productivity, and construct such
pyramids from given data.
 Pyramid of numbers –
Number of individuals at
each trophic level.
 Pyramid of biomass –
Biological mass of the
standing stock at each
trophic level at a
particular point in time
 One point in time that
represent storage – may
be inverted
2.1.4 Explain the principles of pyramids of numbers, pyramids of
biomass, and pyramids of productivity, and construct such
pyramids from given data.
 Pyramid of productivity
– Shows the flow of
energy (rate at which
stock is being generated)
through each level
 No inverted pyramids,
allows direct
comparisons
2.1.5 Discuss how the pyramid structure
affects the functioning of an ecosystem.
 Top carnivores are the first
suffer through ecosystem
disruption, as they are
affected by everything
beneath them.
 Bioaccumulation – Retain
in body tissue (pesticides)
 Biomagnification – Toxins
become more concentrated
further up the food web.
2.1.6 Define the terms species, population, habitat, niche,
community, and ecosystem with reference to local examples.
 Species – A group of
organisms that
interbreed and produce
fertile offspring.
 Fox, Raccoon, Goose
 Population – A group of
the same species living
in the same area at the
same time.
 Flock of Geese
2.1.6 Define the terms species, population, habitat, niche,
community, and ecosystem with reference to local examples.
 Habitat – The
environment in which a
species normally lives.
 Desert, forest
 Niche – Where and how
a species lives. Their
share of habitat and
resources.
 Paradigm (World View)
2.1.6 Define the terms species, population, habitat, niche,
community, and ecosystem with reference to local examples.
 Community – Group of
populations living and
interacting with each other
in a common habitat.
 Community of Minnehaha
Park
 Ecosystem – Community
of interdependent
organisms and the physical
environment they inhabit.
 Minnehaha park as a
whole
2.1.7 Describe and explain population
interactions using examples of named species
 Competition – Either
within a species
(Intraspecific) or
between species
(Interspecific)
 Intra – Wolves
 Inter – Squirrels and
Chipmunks
 Predation – Predator-
Prey relationship
 Bats and insects
2.1.7 Describe and explain population
interactions using examples of named species
 Parasitism –symbiotic
relationship in which
one species benefits at
the expense of the other.
 Ticks, and tapeworms
 Mutualism – symbiotic
relationship in which
both species benefit.
 Lichens (Fungus and
alga)