Parasitism and Mutualism Flashcards
How are parasites and parasitoids different?
Parasites don’t directly kill their host, parasitoids eventually always kill the host
How are parasites classified?
Size (macro vs micro) and where they’re found (ecto vs endo)
What makes a host vulnerable to a parasite?
Weakened immune system, transmission method, lower nutrition, stress
How can a parasite be transmitted from host to host?
Different methods: waterborne, airborne, food, contact.
Indirect contact: uses a vector to get from one host to the next
Direct contact
What are 3 responses of the host to parasites?
Behaviours: grooming, avoiding areas with lots of parasites
Inflammation of infected area
Stimulation of immune system
What effect do parasites have on their hosts?
Can regulate host population, increase probability of host mortality through predation, secondary infections, or reduced survivability
What is the trade-off between transmission and virulence for a parasite?
The more virulent, the harder it is to go from host to host
How can parasitism become mutualism?
If the host starts to tolerate the parasite, can even become beneficial to the host
Why would 2 species become mutualistic?
When the energy costs are outweighed by the benefits of the interactions
What is the difference between symbiotic and non-symbiotic mutualism?
If symbiotic, one organism lives in or on another organism
What are 2 symbiotic mutualistic relationships?
Defensive associations: ants and acacia
Increased pollination: yucca plant and yucca moth
What are 2 non-symbiotic mutualistic relationships?
Pollination: plant loses energy by producing nectar, but receives increased fitness in return
Seed transport: sticky seeds, fruits
Are mycorrhizae mutualists, commensalists, or parasites?
Depends on the situation and the plant species. With low nutrient availability, are mutualists. With high nutrient availability, plant doesn’t get much of a benefit
What are successful, unsuccessful, and non-mutualists?
Successful: give and receive benefits
Unsuccessful: give but don’t receive benefits
Non-mutualists: don’t give or receive
