Producer – makes its own food from simple inorganic substances e.g. plants and some bacteria
Consumer – relies on eating other organisms for food e.g. herbivores, carnivores, omnivores detrivores
and decomposers.
Herbivores –eat only plants and so have teeth incisors, premolars and molars e.g. grasshopper and cow
Carnivores – are meat eaters and have incisors, enlarged carnassials teeth (canines) e.g. dogs and cats
Omnivore – eat both meat and plant matter thus have incisors, canines, premolars and molars e.g. man
Detrivores – feed on the dead e.g. maggots and vultures
Decomposers – breakdown dead organic matter and waste recycling minerals e.g. nitrogen used in
protein synthesis
Trophic level – the level at which an organism feeds e.g. trophic level one is occupied by organisms that
produce their own food
Primary consumers – are organisms that occupy trophic level 2 and feed only on plant or producers of
trophic level one
Arrows of a food chain or web point from food source to the consumer maize  birds
Energy flows in one direction from food to next consumer while minerals are recycled
Energy is lost 90% between trophic levels by feeding, respiration, digestion, excretion and heat.
Since only 10% of the energy available at each trophic/feeding level is passed food chains have an
average limited length of 5 e.g. plant  caterpillar  wasp  bird  hawk
Food web – this is formed by a group of interlinked food chains, that is, at some point a food
chain is linked to another by a common prey or predator.
1. Create a fully labelled food web using the following data
organism
Aphid (insects), rabbits and snails
Toad
Shrew (small rodent)
Snake
owl
What’s for lunch
plant
aphids
Aphids and snails
Rabbits, toads and shrews
Snake and shrew
2. Create 6 food chains that can be food in the food web