1. 2.1 Energy Flow in Ecosystems
Biomass is the __________________of all living things in a given area.
Biomass can also refer to the mass of a particular _____________________, such as _____________________________used to produce ___________________.
Biomass is generally measured in _____________or ______________.
Within an organism’s niche, the organism interacts with the ecosystem by:
Obtaining _________________ from the ecosystem
Contributing_________________to the ecosystem
Plants are called _______________________ because they produce
carbohydrates from _________________________________________.
Consumers get their energy by ______________________________
or other consumers.
Decomposition is the breakdown of ___________ and _______organisms by organisms called decomposers through the process of ___________________________.
Bees are consumers.
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(c) McGraw Hill Ryerson 2007

2. Energy Flow and Energy Loss in Ecosystems: Food Chains
Scientists use different methods to represent ____________ moving through ecosystems.
________________________
Food chains show the flow of
energy in an ____________________.
Each step in a food chain is a __________________________
____________________ = 1st trophic level
____________________= 2nd trophic level
_____________________= 3rd trophic level
__________________________= 4th trophic level
Examples of terrestrial and aquatic food chains
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(c) McGraw Hill Ryerson 2007

3. Energy Flow and Energy Loss in Ecosystems: Food Chains (continued)
Consumers in a food chain can be classified as:
______________________ – consumers that obtain energy and nutrients from dead organisms and waste matter
Examples include _______________________________________.
Detrivores feed at every _________________________.
Detrivores have their own, separate food chains
and are _____________________________.
_______________________ – primary consumers
Herbivores eat _____________ (producers) only.
____________________ – secondary or tertiary consumers
Secondary consumers eat non-producers, such as _______________________.
Tertiary consumers eat _______________________ consumers.
Also called top consumers or top _____________________.
_______________________ – consumers that eat both plants and animals
Examples include ____________________________.
This dung beetle is a detrivore.
See page 61
(c) McGraw Hill Ryerson 2007

4. Energy Flow and Energy Loss in Ecosystems: Food Webs
Most organisms are part of many ______________________.
________________________represent interconnected food chains.
Food webs are models of the _________________________in an ecosystem.
Arrows in a food web represent the _______________________and nutrients.
Following the arrows leads to the top carnivore(s).
This food web represents a terrestrial ecosystem that could be found in ______________________________.
See page 62
(c) McGraw Hill Ryerson 2007

5. Energy Flow and Energy Loss in Ecosystems: Food Pyramids
Food ___________________ show the changes in available energy from one _________________________to another in a food chain.
Energy _______________ at the first trophic level (producers), where there is a large amount of __________________ and therefore much energy.
It takes ____________________________________in one trophic level to meet the energy needs of the next trophic level.
Each level loses large amounts of the energy
it gathers through basic _________________________.
80 – 90 percent of energy taken in by consumers is used in _____________________ in
the body and is lost as _______________energy.
There is very little energy left over for _________________ or increase in biomass.
Ninety percent of this mouse’s food energy is used to maintain its life functions.
See page 63
(c) McGraw Hill Ryerson 2007

6. Energy Flow and Energy Loss in Ecosystems: Food Pyramids (continued)
Food pyramids are also known as ___________________________.
Ecological pyramids may show _______________________________________
__________________________________________________.
The amount of life an ecosystem can contain is based on the _______________ of the ecological pyramid, where producers capture energy from the Sun.
Each level in the energy pyramid = a loss of ________________of total energy available.
Lower trophic levels have much
_____________ populations than upper levels.
This shows the importance of
maintaining large, __________________
populations at the lowest levels
of the ________________________.
See pages
(c) McGraw Hill Ryerson 2007