Understanding:
• Consumers are heterotrophs that feed on living organisms by ingestion
Heterotrophs obtain organic molecules from other organisms via different feeding mechanisms and different food sources
- Consequently, heterotrophs can be differentially classified according to their feeding pattern
Consumers
Consumers are heterotrophs that feed on living organisms by ingestion
- Herbivores are consumers that feed principally on plant matter (e.g. cows, sheep, rabbits)
- Carnivores are consumers that feed principally on animal matter (e.g. crocodiles, wolves, tigers)
- Omnivores are consumers that have a principle diet composed of both plant and animal matter (e.g. pandas, humans)
Scavengers
Scavengers are a type of consumer that principally feed on dead and decaying carcasses rather than hunting live prey
- Examples of scavengers include hyenas, vultures and carrion birds (such as crows)
Understanding:
• Detritivores are heterotrophs that obtain organic nutrients from detritus via internal digestion
Detritivores
Detritivores are a type of heterotroph that obtains nutrients from non-living organic sources, such as detritus and humus
- Detritus is dead, particulate organic matter – such as decaying organic material and fecal matter
- Humus is the term given specifically to the decaying leaf litter intermixed within the topsoil
- Detritivores include dung beetles, earthworms, woodlice, snails and crabs
Understanding:
• Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion
Saprotrophs
Saprotrophs live on (or in) non-living organic matter, secrete digestive enzymes into it and absorbing the products of digestion
- Unlike other types of heterotrophs, saprotrophs do not ingest food but use enzymatic secretion to facilitate external digestion
- Because saprotrophs facilitate the breakdown of dead organic material, they are commonly referred to as decomposers
- Examples of saprotrophs include bacteria and fungi
