FOOD WEBS
Food webs show the interrelationship between some (not all) organisms in an ecosystem. Each
organism shown in a food web is representative of that species as a whole. When organisms are
connected by arrows, it shows a reliance of one organism upon another for food. It is important to
be able to name parts of the food web, but also to predict the outcomes for related organisms if
one or more are no longer present due to migration, local or widespread extinction, seasonal
variation etc or expand greatly in population.
1. Name the parts of the food web below:
2. Predict the effects of the following events:
a) “Prickly Pear Disease” kills off most of the prickly pear species.
b) Scorpions decrease in number due to pesticides.
c) Beetles are scarce in number.
d) Is it more or less advantageous for an organism to have multiple food sources? Justify your
answer.