Exam 1 Flashcards
What are the five types of pathogens?
Viruses, bacteria, protozoa, fungi, worms
Pathogen
a disease-causing (infectious) agent that can alter the function and behavior of the organism in question
Epidemiology
Understanding the transmission and impact of disease at the population level. Studied in human, domestic, and wildlife populations
Veterinary medicine
determining the causes of disease and developing ways of treating or preventing disease in animals
Disease ecology
the ecological examination of disease
Disease
any deviation from the normal structure or function of any body part, organ, or system that is exhibited by a characteristic set of signs and symptoms
Sign
any objective evidence of disease that can be measured and is physically noticeable to the observer
Symptom
subjective and can only be noticed by the patient
Intrinsic
generated from within the body
Extrinsic
diseases that arise from the environment outside of the body
Infectious
caused by pathogenic microorganisms, including viruses, bacteria, fungi, protozoa, multicellular parasites, and abnormal proteins known as prions, can be spread directly or indirectly from one organism to another
Non-infectious
not caused by a pathogen and cannot be spread from one organism to another
Macroparasite
only completes part of its life cycle in one host, spending the rest of its life free-living or with a different host
Microparasite
completes its life cycle in one host
Virulence
degree of reproduction and impact to host metabolism and homeostasis
Infectivity
ability of pathogen to invade and harm a targeted host organism
Latent infection
do not always show symptoms, and do not always cause harm, but they consistently present in the host
Chronic infection
remain in the host after the initial infection and cause re-occurring or chronic disease
Slow infections
gradually increase in number within a host over long periods of time
Acute infections
Short with rapid host recovery
Persistent infections
continuously present in the host or for an extended period of the host’s lifespan
Vertical transmission
the transmission of an infectious disease from mother to child
Horizontal transmission
when an infectious agent is transferred between members of the same species, but the members are not in a parent-child relationship
Direct transmission
If a disease is transmitted through contact of potential hosts
Indirect transmission
Occurs through environmental means such as water, air, or terrestrial surfaces
Vector
organisms that carry and transmit an infectious pathogen to a naive host
Mechanical vector
passively transmit a pathogen
Fomites
abiotic agents that carry pathogens
What was Koprivnikar et al. about?
It was the frog/tadpole sutdy about adaptive anti-parasite behavior in hosts
What was the knowledge gap that motivated the Koprivnikar et al. study?
It was unknown if tadpoles avoid parasitism by increasing or decreasing activity
Prevalence
the proportion of individuals in a population with a disease
How do you calculate prevalence?
number of occurrences/population size at a specific point in time x100
Incidence
number of new cases in a population over a time period
Birthrate
number of live young born per female in a period of time
R0
net reproductive rate
What does the number of R0 represent?
If R0 < 1, the population is decreasing, if R0 = 1, the population is stable, if R0 > 1, the population is increasing
lx
proportion of individuals surviving to each age class with respect to the initial number of individuals at time zero, Nx/N0
dx
proportion of individuals dying between age classes x and x+1, lx - lx+1
qx
proportion of individuals dying at each age class (x), with respect to the initial number of individuals at time zero, (N0 - Nx)/N0
r
per capita rate of increase, B-D
Spatial distribution
the location of individuals over particular area due to biological or abiotic factors
Evolution
the pattern of descent with modification in a population such that there are changes in traits of populations over time
What are the 5 conditions necessary to maintain constant allele frequency?
- random mating
- no mutations
- large population size (no genetic drift)
- no immigration (gene flow)
- all genotypes have equal Darwinian fitness (no selection)
Stabilizing selection
population shows normal distribution of a phenotype
Directional selection
population shows normal distribution of a phenotype, natural selection favors one extreme genotype
Disruptive selection
populations with more than one abundant genotype, natural selection favors two or more extreme genotypes
Bottleneck effect
when something (abiotic or biotic) reduces large population dramatically, leading to inbreeding between individuals and loss of genetic diversity
What was the main concept in de Roode et al.?
Understanding the evolution of parasite virulence
