SCIENCE - YEAR 7 BIOLOGICAL SCIENCES BIOTIC FACTORS – Food Chains and Food Webs The animals and plants which live together in a particular place usually depend on each other for food. A food chain shows the way in which energy flows from one living thing to another. An example of a food chain is shown below: grass rabbit fox The arrows show the direction in which the energy (food) goes. Food chains usually begin with green plants, because they are (producers). On the other hand, animals cannot make their own food. They rely on green plants or other animals for their food and are called consumers. The number of links in a chain is commonly 4 and seldom exceeds 6 members. A food web is a series of inter-related food chains. 1. Construct a food web that includes all the feeding relationships in the table below. Arrows may cross each other if necessary. On completion there should be 17 arrows. Organism Frog Duck Crustaceans Water snails Fish Fox Tadpole Insect Kookaburra Food(s) eaten Water snails, insects Water snails, tadpoles, algae, crustaceans Algae Algae, grass Crustaceans, algae Ducks, frogs Algae Grass Frogs, insects 2. Using the organisms in the food web: a) Construct the longest food chain in the food web. b) Name 2: - Producers i) ______________________ ii) _______________________ - First order consumers (herbivores) i) ________________________ ii) ________________________ Second order consumers (carnivores) i) ________________________ ii) ________________________ 3. Name an omnivore in the food web. ______________________ 4. Construct a food web using the information in the table. Organism Food Eaten Dingo Wallaby, Possum, Feral Cat Mouse Grass/Grain/Berry Possum Insects, Grass/Grain/Berry Wallaby Grass/Grain/Berry Feral Cat Possum, Mouse Insect Grass/Grain/Berry Eagle Mouse, Possum Organism Frog Duck Crustaceans Water snails Fish Fox Tadpole Insect Kookaburra Food(s) eaten Water snails, insects Water snails, tadpoles, algae, crustaceans Algae Algae, grass Crustaceans, algae Ducks, frogs Algae Grass Frogs, insects
