What is the principal source of energy?
The sun
food chain
shows how energy is transferred from one organism to the next.
What does a food chain always begin?
producer
food web
a network of interconnected food chains, showing multiple feeding relationship
producer
make their own organic nutrients (usually using sunlight in photosynthesis).
consumer
Organisms that get energy by feeding on other organisms.
what can consumers be?
herbivores, carnivores, omnivores.
primary consumer
Consumers that get their energy by feeding on producer
secondary consumer
gets energy by feeding on primary consumer
tertiary consumer
gets energy by feeding on secondary consumer
quaternary consumer
gets its energy by feeding on a tertiary consumer
herbivore
An animal that eats plants.
carnivore
An animal that eats other animals.
omnivore
gets energy by eating both plants and animal
decomposers
Organisms that feed on dead or waste material, recycling nutrients.
impact of humans
-overharvesting
-introducing foreign species
overharvesting
reduces food availability for other organisms.
Introducing foreign species
Introducing foreign species can disrupt food chains and food webs
trophic level
The position an organism occupies in a food chain or web.
How much energy is passed on from each level?
10%
How is energy lost in a food chain + web?
lost as:
-heat energy
-lost as feces
-used in metabolism
energy loss calculation
(Energy at lower trophic level/Energy at higher trophic level)×100
Why are food chains very short?
energy transfer between levels is highly inefficient
Explain why eating at a lower trophic level is more energy efficient?
because plants are at the first trophic level and contain more available energy
