2.4 Modes of nutrition Flashcards
what is nutrition
the process by which organisms use nutrients to obtain
- energy to maintain functions of life
- matter to create and sustain function
what are the 2 main modes of nutrition
- autotrophic nutrition
- heterotrophic nutrition
what are the 2 types of autotrophic nutrition
- photosynthesis
- chemosynthesis
explain autotrophic nutrition
autotrophic = self feeding
autotrophs produce their own food by using inorganic materials
explain photosynthesis
light is the source of energy for the production of food
it is used by all green plants, algae and some bacteria.
explain chemosynthesis
chemical activity is the source of energy for the production of organic compounds
it is used by autotrophic bacteria
what are the 4 types of heterotrophic nutrition
- holozoic feeders
- Saprophytes
- parasites
- mutualistic feeders
what is heterotrophic nutrition
heterotrophic = fed by others
heterotrophs food is processed as it passes along the gut
in advanced organisms(with more varied diet), gutis divided into various parts
examples of heterotrophs:
animals
fungi
some bacteria
some protists
what are holozoic feeders
nearly all animals
- a method of nutrition which involves digestion of liquid/solid organic material, broken down by digestion
What is a holozoic detritivore
obtain energy from dead and decaying material - insects
what are saphrophytes
obtain energy from dead and decaying material but DO NOT have a specialised digestive system
how do saprophytes feed
by secreting enzymes onto their food OUTSIDE THE BODY.
They then absorb the digested/soluble products across the cell membrane (diffusion).
THIS IS EXTRACELLULAR DIGESTION
give examples of saprophytes
all fungi
some bacteria
what are parasites
organisms which live on or in another organism(called the host), obtaining nourishment at the expense of the host.
HIGHLY SPECIALISED ORGANISMS - lots of adaptation shown
what are ectoparasites
parasites which live on the surface of the host
what are endoparasites
parasites which live inside the body of the host
what is an example of a ectoparasite
a flea
what is an example of a endoparasite
a tapeworm
what is mutualism also known as:
symbiosis
what is mutualism
a close association between members of 2 species, where both members gain some benefit from the relationship
give an example of mutualism/symbiosis
microbes(bacteria) in the gut of sheep/cows.
- herbivores do not produce cellulase which is needed to digest cellulase. Bacteria which live in rumen do produce cellulase.
in return, bacteria gain other digestive products, warmth and protection.
