4.2.2 Food Webs Flashcards
What is a food web
A food web is a network of interconnected food chains
Food webs are more realistic ways of showing, what?
connections between organisms within an ecosystem as animals rarely exist on just one type of food source
(Food Web Definitions) Producers
Organisms that produce their own organic nutrients that usually use energy from sunlight. Plants are producers as they carry out photosynthesis to make glucose.
(Food Web Definitions) Herbivore
An animal that gets its energy by eating plants
(Food Web Definitions) Carnivore
An animal that gets its energy by eating other animals
(Food Web Definitions) Primary Consumers
Herbivores - They feed on producers (plants)
(Food Web Definitions) Secondary Consumers
Predators that feed on primary consumers
(Food Web Definitions) Tertiary Consumers
Predators that feed on secondary consumers
(Food Web Definitions) Decomposers
Bacteria and Fungi that get their energy from feeding off dead and decaying organisms and undigested waste (such as faeces) by secreting enzymes to break them down.
Food webs give us a lot more information about, what?
the transfer of energy in an ecosystem
What do Food Webs also show?
interdependence – how the change in one population can affect others within the food web
Most of the changes in populations of animals and plants happen as a result of, what?
human impact – either by overharvesting of food species or by the introduction of foreign species to a habitat
interdependence can have what type of effect?
long-lasting knock-on effects on organisms throughout a food chain or web
Exam Tip
Questions about interdependence in food webs are common and easy to gain marks on if you answer them fully and correctly.
Do not say an animal or plant would ‘die out’ as this is unlikely to happen – stick to using the words decrease or increase. If in doubt, always give your reason for the increase or decrease in population.
