Component 3.3 - Modes Of Nutrition Flashcards
What are autotrophic organisms?
Make their own food from the simple inorganic raw materials carbon dioxide and water.
What specific types of autotrophic organisms exist?
Photoautotrophic: organisms that use light as the energy source and perform photosynthesis e.g all green plants
Chemoautotrophic: They use energy from chemical reactions e.g all prokaryotes
What type of nutrition do autotrophic organisms carry out?
Holophytic
Why are organisms that are chemoautotrophic no longer dominant life forms?
Because it is less efficient than photosynthesis
Give examples of heterotrophs
Animals, fungi, some protoctista and some bacteria
Describe what a heterotrophic organism is
They cannot make their own food and consume complex organic molecules produced by autotrophs. They either eat autotrophs or organisms that have eaten autotrophs.
Explain how saprotrophic nutrition works in fungi
They have no specialised digestive system so they secrete enzymes onto food material for extracellular digestion and this is followed by absorption of the products into the organism/
What’s the difference between ecto and endoparasites?
Endoparasites live in the body of the host but ectoparasites live on its surface
Describe what parasitic nutrition is
A type of heterotrophic nutrition that involves obtaining nutrition from another living organism, the host.
What is the effect on the host of parasitic nutrition?
Parasite’s host always suffers some harm and often death
Describe holozoic nutrition
A type of heterotrophic nutrition that involves ingestion, digestion, absorption, assimilation and egestion
Give examples of animals that perform holozoic nutrition
Herbivores - eat plant material
Carnivores - animals that eat other animals
Omnivores - eat plant and animal material
Detritivores - feed on dead and decaying matter
