Mutualism
What is the definition of mutualism?
Mutualism is a symbiotic relationship between two (or more) species where each partner gets a benefit from the other.
What is commensalism?
Commensalism is the type of symbiotic relationship where one species benefits while the other is neither affected positively or negatively.
What is the mutualistic relationship between flowers and bees?
Bees get nectar, flowers get pollination.
Give one example of commensalism in the ocean.
Remora fish hitching rides on sharks.
Why is clownfish and sea anemone mutualism?
Clownfish gets shelter while anemone gets cleaning and nutrients
Why are barnacles on whales NOT considered parasitism?
Barnacles benefit while whales aren’t harmed or helped much.
Is the oxpecker bird on rhinos mutualism, parasitism, or commensalism? Why?
Trick Question: Used to be considered commensalism until Ox started benefiting from the oxpeckers. Now it is considered parasitism because birds peck wounds.
Crows follow wolves and wait for them to finish a kill to eat the scraps.
Why is this NOT parasitism?
Because the wolves lose nothing - their access to meat is unaffected. Crows simply take leftovers they wouldn’t eat anyway.
Explain how gut bacteria in humans show obligate mutualism.
Humans need vitamins they make and bacteria need a stable home to survive.
Burdock seeds cling to animal fur and are carried long distances.
Many people mistake this for mutualism or parasitism.
Why is it actually commensalism?
Animals aren’t harmed (seeds don’t dig into skin), and they gain no benefit. Only the plant gains reproductive dispersion (higher fitness).