symbiosis

• symbiosis

  the co evolved, intimate relationship between members of 2 different species
• parasites often have limited metabolism and cannot survive out of contact with a host
• parasitic relationship

  host - dog: loses energy and nutrients when blood is lost

  parasite - flea: gains nutrients and energy by feeding on dog's blood
• parasitic transmission

  direct contact - parasite passed directly from individual to individual eg. lice, rabies

  resistant stages - parasite produces relitavley inactive stages (eggs) that are resistant to environmental conditions

  vector - parasite temporarily occupies another species which passes it onto a new host (secondary host) eg. malaria
• intermediate hosts

  allows some species to complete thier lifestyles. if entire lifecycle of parasite happens in an organism - a host
• paratism

  parasites gain nutrients and the host is harmed by this loss
• mutualism

  when both organisms benefit in an independent relationship
• mutualistic relationship eg

  cellulose digesting organisms - receive protection, warmth and a constant food supply

  herbivores (cows) - the microorganisms produce enzymes which help the cow digest cellulose into simple sugars