Food Webs Flashcards
All 6 cards in this deck
What is a food web?
Several interconnected food chains in an ecosystem, showing all the feeding relationships.
What are the steps to predict the effect of removing one species from a food web?
e.g. all foxes are removed from a web where fox eats rabbit and rabbit eats grass- Find what the species eats: foxes eat rabbits.
- Prey increase because fewer are eaten: more rabbits.
- Follow the effect on: less grass, as more rabbits eat it.
In a food web, what usually happens to a prey population if its predators are removed?
It increases, because fewer prey are eaten/killed so more survive to reproduce.
In a food web, what usually happens to a predator population if its prey population falls?
It decreases, because there is less food available.
True or false? An organism in a food web can belong to more than one trophic level.
True. An omnivore may be a primary consumer in one chain and a secondary consumer in another.
True or false? In a food web, a change in one population only affects the species it directly eats.
False. Effects spread through the web to species that are not directly linked to it.