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. See pages 56 - 59 (c) McGraw Hill Ryerson 2007

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 See pages 59 - 60 (c) McGraw Hill Ryerson 2007

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

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

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

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 63 - 64 (c) McGraw Hill Ryerson 2007