1 – Introduction Flashcards
1
Q
Relationship between organisms
A
- Symbiosis: Organisms in close association with one another
a. Mutualism (both benefit, ex. bacteria inside rumen)
b. Commensalism (Neutral, ex. amoeba inside cecum of cattle)
c. Parasitism (one benefits, causing negative effects)
2
Q
Parasitism
A
- Ecological relationship where parasite
o Depends on host for survival
o Negative effects on host
o Greater fecundity than host
o Over-dispersed host distribution - Endoparasites: internal, causing INFECTIONS
- Ectoparasites: external, causing INFESTATIONS
3
Q
Infective stage
A
- Life cycle stage INFECTIVE for host
4
Q
Shed stage
A
- Stages PASSED by host (may or may not be infective)
5
Q
Pre-patent period (PPP)
A
- Time between infection and shedding of next generation of parasites
6
Q
Patent period (patency)
A
- Period of shedding
7
Q
Prevalence
A
- Proportion of infected hosts
8
Q
Intensity
A
- Number of parasites per host
9
Q
Host specificity
A
- How restricted a parasite is to certain host species
10
Q
Direct life cycle
A
- Definitive host to shed stages to environment to infective stages and back
11
Q
Indirect life cycle
A
- Definitive host to shed stages to environment to intermediate host(s) w/juvenile stages (no sexual reproduction)
12
Q
Definitive host (DH)
A
- Obligatory for ALL parasites
- NEED host to survive/reproduce
- Only host in direct life cycle
- Ex. endoparasite undergoes sexual reproduction in the DH
13
Q
Intermediate Host (IH)
A
- Obligatory for endoparasites with INDIRECT life cycles
o Cestodes, trematodes
o Some nematodes and protozoans - Parasite undergoes development WITHIN IH
o Never sexual reproduction
o Sometimes asexual reproduction (amplification)
14
Q
Paratenic host
A
- HELPFUL for transmission, but not required
o Infection but no reproduction, no development
15
Q
Vector
A
- MOBILE transport host
- Biological or mechanical
- Many ectoparasites
- Some endoparasites
