SNC1D - Sustainable Ecosystems
RHSA
Food Webs, Food Chains and Trophic Levels
A food web shows the many complex feeding
relationships in an ecosystem. Food chains
describe the feeding relationships among
organisms starting with a producer and ending
with a consumer.
A FOOD WEB
A food chain is
one path through a
food web. Food
chains use arrows
to show energy
flow.
What are two food
chains in this food
web?
a. grass  snail  bird  eagle
b. grass  caterpillar  lizard
SNC1D - Sustainable Ecosystems
RHSA
Energy flows through an ecosystem in a food
chain. Each step in a food chain is considered a
higher trophic level or energy level. Energy is
measured in joules (J) or calories.
FOOD WEB TROPHIC LEVELS
SNC1D - Sustainable Ecosystems
RHSA
As energy transfers through a food chain, most
of the energy is lost to heat, running, feces, and
only about 10% of the energy eaten is stored in
the cells. This energy transfer is shown in an
energy pyramid.
- Food Chain Song 2:46
http://www.youtube.com/watch?v=TE6wqG4nb3M&feature=related
- Food chain on a farm 1 min
http://www.bbc.co.uk/learningzone/clips/food-chains-on-a-farm/2313.html
SNC1D - Sustainable Ecosystems
RHSA
Food Webs, Food Chains and Trophic Levels
A food _______ shows the many complex feeding relationships in an ecosystem.
Food chains describe the feeding relationships __________________________
___________________________________________________ .
A food chain _________________________________. Food chains use _______
to show energy flow.
What are two food chains in this food web?
a.
b.
SNC1D - Sustainable Ecosystems
RHSA
Energy flows through an ecosystem in a ________________ .
Each step in a food chain is considered a higher ____________ level or energy
level. Energy is measured in _______________________________________
_____________________________.
FOOD WEB TROPHIC LEVELS
SNC1D - Sustainable Ecosystems
RHSA
As energy transfers through a food chain, some of the energy is lost to heat,
running, feces, and only about ________ of the energy eaten is stored in the cells.
This energy transfer is shown in an ________ _____________.
- Food Chain Song 2:46
http://www.youtube.com/watch?v=TE6wqG4nb3M&feature=related
- Food chain on a farm 1 min
http://www.bbc.co.uk/learningzone/clips/food-chains-on-a-farm/2313.html