Adaptation for nutrition

• Autotrophic organisms make their own food from carbon dioxide and water
• Photoautotrophic organisms use light as energy and perform photosynthesis. This type of nutrition is described as holophytic
• Green plants, some protoctista and some bacteria are Photoautotrophic
• Chemoautotrophic organisms use the energy from chemical reactions to make their own food
• Chemoautotrophic organisms are all prokaryotes and they perform chemosynthesis. it is less efficient than photosynthesis so they are no longer dominant life forms
• Heterotrophic organisms cannot make their own food and consume complex organic molecules produced by autotrophs (they are consumers)
• All animals are consumers and dependent on producers for food other organisms include fungi, some protoctista and some bacteria
• Saprotrophic nutrition (used by saprotrophs) is used by all fungi and some bacteria and feed on dead or decaying matter
• Saprotrophs have no specialised digestive system and secrete enzymes including proteases, amylase, lipase and cellulase on food material outside body for extracellular digestion.
• Decomposers are microscopic saprotrophs and their activity is important in decaying leaf litter and recycling nutrients such as nitrogen
• Parasitic nutrition means obtaining nutrition from another living organism (The host) and it always suffers some harm or often death
• Endoparasites live inside the body of the host
• Ectoparasites live on the surface of its host
• Tape worm (taenia Solium), head lice (pediculus capitis), fungus causing potato blights (Phytophthora infestans) and plasmodium (malaria) are examples of parasites
• Holozoic nutrition is used by most animals. they ingest, digest, food and egest the indigestible remains. food is processed inside the body by a specialised digestive system. digested materials are absorbed into the body tissues and used by cells
• Herbivores are animals that only eat plant materials
• Carnivores are animals that only eat other animals.
• Omnivores are animals that eat both plant and animal materials
• Detritivores feed on dead or decaying material