L3 Mutualism PDF

More Ecological relationships Symbiosis Sometimes two quite different organisms live and function together in a close association, to the benefit of at least one of them. Different species living together in a close partnership is called symbiosis. Each species is called a symbiont. M...

More Ecological relationships Symbiosis Sometimes two quite different organisms live and function together in a close association, to the benefit of at least one of them. Different species living together in a close partnership is called symbiosis. Each species is called a symbiont. Mutualism, commensalism and parasitism are all examples of symbiotic relationships. Symbiosis Symbiosis describes the close and persistent (long- term) interaction between two species Symbiotic relationships can be required for survival or advantageous without being strictly necessary  Symbiotic relationships can be beneficial to either one or both organisms in the partnership: Mutualism – Both species benefit from the interaction Commensalism – One species benefits, the other is unaffected Parasitism – One species benefits to the detriment of the other species What is happening here? What is happening here?  Mutualism Oxpeckers stand on cattle or other large animals and feed on the parasites in the hair and on the skin of their host. The birds benefit from easy access to a food source The large animal benefits from parasite removal Mutualism Definitions Mutualism is a partnership between two different kinds of organism where both of them benefit. Mutualism describes an ongoing interaction between two species whereby both species benefit from the interaction Mutualism is a prolonged association of two different species in which both partners gain some benefit. Mutualism Some species of anemone coexist with clownfish. Each species is highly dependent on the other for survival.  In return for a safe and protective home, the clownfish benefits the anemone in several important ways. These include cleaning the anemone, providing nutrients in the form of its waste, and scaring away predatory fish that want to eat the anemone such as the butterflyfish.  Mutualism mistletoe birds and mistletoe plants. The birds depend on mistletoe fruits for food and, in turn, disperse the seeds for these plants. The birds eat the fruit but the seed is not digested. It passes out in their waste, it can then germinate and grow into a new plant.  Many mammals that consume plants have bacteria living in their guts, which help them to digest the grass. Koalas have a long caecum. The caecum contains millions of bacteria which break down the plants into smaller molecules which are easier to absorb.  Honey bees get food (nectar) from flowers and distribute pollen between plants (mediating plant reproduction) Plover birds pick food from the jaws of crocodiles, cleaning the crocodile's teeth in the process Zooxanthellae (algae) live within the protective environment of the coral and when they photosynthesise they provide glucose (food) for the coral.  Reef-building coral will form a symbiotic relationship with the photosynthetic unicellular algae – Zooxanthellae The algae lives within the cells of the coral  The coral provides the algae with a protective environment (a home) and carbon dioxide- this is a waste gas from respiration in the coral but an essential requirement of photosynthesis needed by the algae The zooxanthellae, in turn, provides the coral polyps oxygen and glucose produced via photosynthesis Symbiosis and mutualism - notes There are three types of symbiotic relationship: mutualism, commensalism and parasitism. Mutualism is a prolonged association between two different species where both of them benefit from the interaction. Outline these symbiotic relationships: Coral and Zooxanthellae Oxpeckers and zebra Sea anemones and clownfish Mistletoe birds and mistletoe plants Honey bee and flowering plants Crocodiles and plover birds Koala and bacteria in their digestive system