Lecture 14: Animal Symbiosis Flashcards
Symbiosis
“Living together”
– a persistent association between two or more unrelated organisms
Host
PROVIDER of resource
Symbiont
CONSUMER of resource
Interaction is classified by the effect of the …
symbiont on the host
Types of symbiotic relationships
- mutualism
- commensalism
- parasitism
mutualism
+ + interaction
both host and symbiont benefit
based on reciprocity
greater reward than cost
Note: Based on persistent association
Plant/pollen
Why doesn’t the plant/pollunator relationship qualify as symbiosis?
It is mutualistic because they both benefit but not a symbiosis because its a brief interaction. Symbiosis requires persistent association.
commensalism
+ 0 interaction
symbiont has a positive Benefit
host has no benefit or loss
-ie barnacle(home) and whale(no impact)
parasitic
+ x interaction
symbiont has a positive benefit
host has loss or affected negatively
ie- tapworm and dog
symbiotic interactions are ….
content dependent (more like a spectrum of interactions)
Zooxanthellae
photosynthetic algae found in coral and other marine invertebrates
facultative mutualism
independently
obligate mutualism
organisms rely on each other for survival
Endosymbiosis
internal symbiotic partner
what two ways can an organism gain symbionts?
- horizontal transmission
- vertical transmission
horizontal transmission
symbiont acquired through environment ( food, air, et)
vertical transmission
symbiont acquired through mother
2 primary symbiosis
(1) prokaryotic cell engulfs heterotrophic cell
2) organism with mitochondria engulfed another prokaryote but this time photosynthetic (eventually chloroplast
Mutualisms: Endosymbiosis
- Allows organisms to acquire novel traits and metabolic capabilities
- Create habitats impossible otherwise
Mutualisms: Endosymbiosis
- Allows organisms to acquire novel traits and metabolic capabilities
- Create habitats impossible otherwise
Functions of mutualism
Nutrition (digestion)
Defense (predation prevention)
Communication
Types of defense provided in mutualism
(1) Predation prevention
(2) Toxin production
(3) Pathogen Prevention
Types of defense provided in mutualism
(1) Predation prevention
(2) Toxin production
(3) Pathogen Prevention
Explain how Wholbachia helps with pathogen prevention.
protects against RNA viral infection by interfering with replication
