Lecture 23 - Organism Defence Flashcards
pathogen vs parasite
pathogen
- > organisms that cause disease
parasites
- > feed on hosts and benefit at their expense
describe animal responses to pathogens
1. Innate immunity (all animals)
- > recognize traits shared by pathogens using small set of receptors
- > rapid
2. Adaptive immunity (vertebrates only)
- > recognize traits specific to a pathogen using a vast array or receptors
describe land plants response to pathogens
- > response triggered by presence of pathogen (or herbivore)
- > can prevent spreasd of infection
what happens when dutch elm disease (wilt disease) infects organism
- > innate defences become overwhelmed because of no induced antimicrobial defences (no evolutionary history w/pathogen)
- > plant blocks zylem to prevent spread of fungi (kills rapidly)
list some examples of behavioural defense
- > herds/schools
- > hiding
- > fleeing
- > self defence (rare)
biological defences that prevent predatation
chemical defences
- > toxins, scents
physical defences
- > morphology (porcupine)
coloration
- > cryptic: hide from predator
- > aposematic: toxin present (colour shows if toxic)
mimicry
- > batesian: harmless but pretend otherwise
- > mullerian: unpalatable and resemble eachother
what are protecting relatives and how are they advantageous
some animals serve and protect others (altruistic)
- > advantage = inclusive fitness
* fitness acheived by helping close relatives reproduce
what are the determinants of protective relatives and how does Hamiltons rule apply to them
3 determinants
- benefit to recipient (B)
- cost to provider (C)
- relatedness of individual (r)
Hamiltons rule
- > if rB > C, natural selection favours altruism
interspecific vs intraspecific defence of resources
Interspecific
- > resource defense between species
Intraspecific
- > resource defense within a species
