Symbiotic Relationships Flashcards
What does symbiosis refer to?
Symbiosis refers to the living together of two or more species of organism.
What is mutualism?
Mutualism is when both organisms benefit.
Example: Lichen, where algae and fungus form a mutualistic relationship.
How do algae and fungi interact in a lichen?
Algae need a moist environment to survive and cannot live on dry land. The fungus provides algae protection from the environment.
How do fungi benefit from their relationship with algae?
Fungi obtain nutrients from the algae, which can produce food by photosynthesis.
What is commensalism?
Commensalism is when one species benefits while the other does not benefit nor is it harmed.
What is parasitism?
Parasitism is when one species benefits while the other species is harmed.
Are all bacteria in our intestines harmful?
Not all bacteria found in our intestines are harmful.
What role does Escherichia coli (E. coli) play in the human gut?
Mutualistic bacteria such as E. coli live on the undigested remains of food in the gut and make vitamin K, which can be used by humans.
Vitamin K plays an important role in blood clotting.
Where else are mutualistic bacteria found?
Mutualistic bacteria are also found in the digestive tracts of ruminants and termites, responsible for the digestion of cellulose into simple sugars.
Why do higher plants require nitrogen?
Higher plants require nitrogen to manufacture proteins.
Can plants use nitrogen directly from the atmosphere?
Plants cannot use nitrogen directly from the atmosphere.
In what form do plants require nitrogen?
Plants require nitrogen in the form of nitrates.
What do some soil bacteria do regarding nitrogen?
Some soil bacteria can convert free nitrogen to nitrates that can be used by plants.
Where do some nitrogen-fixing bacteria live?
Some nitrogen-fixing bacteria live in special nodules in the roots of leguminous plants (i.e. pod-producing plants such as beans and peas).
What is the mutual benefit between plants and nitrogen-fixing bacteria?
Nitrogen-fixing bacteria produce nitrates for the plants while the plant provides the bacterium with a place to live, carbohydrates, and water.
