Energy Flow Worksheet (Answers)

Energy Flow Feeding Patterns Define trophic level The position an organism occupies within a feeding sequence ………………………………………………………………………………………………………………………………………………….......... Producers always occupy the first trophic level ………………………………………………………………………………………………………………………………………………….......... Use the following animals (and any type of plant matter) to construct three food chains with four levels Grass Rabbit Wolf Fox Food Chain: ………………………. ⇒ ………………………… ⇒ ………………………… ⇒ ……………………… Shrub Slug Spider Lizard Algae Shrimp Fish Turtle Food Chain: ………………………. ⇒ ………………………… ⇒ ………………………… ⇒ ……………………… Food Chain: ………………………. ⇒ ………………………… ⇒ ………………………… ⇒ ……………………… Differentiate between a food chain and a food web Food chains show the linear feeding relationships between species in a community ………………………………………………………………………………………………………………………………………………….......... Food webs show inter-related feeding relationships between species (i.e. multiple food chains) ………………………………………………………………………………………………………………………………………………….......... In food webs, organisms can have multiple food sources, and thus can occupy multiple trophic levels ………………………………………………………………………………………………………………………………………………….......... State what an arrow represents in a food chain or food web The arrow represents the direction of energy flow (points towards the consumer) ………………………………………………………………………………………………………………………………………………….......... Distinguish between herbivores, carnivores and omnivores Herbivore: Feeds exclusively on plant matter ………………………………………………………………………………………………………………………………………………….......... Carnivore: Feeds exclusively on animal matter (i.e. meat-eaters) ………………………………………………………………………………………………………………………………………………….......... Omnivores: Feeds on both plant and animal matter ………………………………………………………………………………………………………………………………………………….......... Construct a food web from the following information (including trophic levels occupied per organism) • Red foxes feed on raccoons, crayfish, grasshoppers, red clover, meadow voles and squirrels • Red clovers are eat by grasshoppers, muskrats, red foxes and meadow voles • Meadow voles, squirrels and raccoons all eat parts of the white oak tree • Crayfish feed on green algae and detritus, and they are eaten by muskrats and red foxes • Raccoons feed on muskrats, meadow voles, squirrels and white oak Green Algae Crayfish Red Clovers Grasshoppers White Oak Tree Meadow Voles Squirrels Muskrats Raccoons Red Foxes Energy Transfer State the initial source of energy for almost all communities Light (i.e. from the sun) ………………………………………………………………………………………………………………………………………………….......... How efficient are most biological energy transformations? Most energy transformations are only ~ 5 - 20% efficient ………………………………………………………………………………………………………………………………………………….......... List three ways in which energy may be lost from one trophic level to the next As heat 1. …………………………………………………………………………………………………………………………………………………... Converted into other form of energy (e.g. kinetic energy) 2. …………………………………………………………………………………………………………………………………………………... Stored chemical energy remains unconsumed 3. …………………………………………………………………………………………………………………………………………………... Describe the flow of energy in ecosystems Light energy (from the sun) is the initial energy source for almost all communities ………………………………………………………………………………………………………………………………………………….......... It is converted into chemical energy (organic molecules) by producers / autotrophs via photosynthesis ………………………………………………………………………………………………………………………………………………….......... The organic molecules are converted into a usable energy form (ATP) via cell respiration ………………………………………………………………………………………………………………………………………………….......... Heterotrophs (consumers) ingest these organic compounds in order to undergo cell respiration ………………………………………………………………………………………………………………………………………………….......... Energy transformations are only ~10% efficient, the majority of the energy is lost as heat ………………………………………………………………………………………………………………………………………………….......... With the aid of the following diagrams, explain the reasons for the shape of a pyramid of energy fox wolve s reindeer moss rabbits insects grass Pyramids of energy show the amount of energy at each trophic level of a food chain ………………………………………………………………………………………………………………………………………………….......... They will never appear inverted as some of the energy at each trophic level is always lost upon transfer ………………………………………………………………………………………………………………………………………………….......... Each level should be roughly one tenth the size of the previous level (as transformations are ~10% efficient) ………………………………………………………………………………………………………………………………………………….......... Producers will always occupy the bottom level of a pyramid of energy ………………………………………………………………………………………………………………………………………………….......... State the units of measurement used in a pyramid of energy kJ . m-2 . year-1 (energy per area per time) ………………………………………………………………………………………………………………………………………………….......... Define biomass Biomass is the total dry weight of organic matter in organisms or ecosystems ………………………………………………………………………………………………………………………………………………….......... (i.e. the entirety of all biologically produced organic matter - carbohydrates, proteins, etc.) …………………………………………………………………………………………………………………………………………………..........