BI107 Exam 3
Terms
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- population
- a group of individuals from the same species that live in the same area at the same time
- demography
- the study of factors that determine the size and structure of populations through time
- immigration
- individuals enter a population by moving from another population
- emmigration
- individuals leave a population and join another population
- generation
- the average time between a mother's first offspring and her daughter's first offspring
- life table
- summarizes the probability that an idividual will survive and reproduce in any given year
- Survivorship
- is the proportion of offspring produced that survive, on average, to a particular age.
- cohort
- a group of the same age that can be followed through time
- What is a Type I Survivorship curve and give an example of an organism who has it?
- Type I: High Survivorship until old age where the Survivorship decreases. An example would be elephants or humans.
- What is a Type II Survivorship curve and give an example of an organism who has it?
- Type II: Steady decrease in survivorship as age increases. An example would be birds or other small organisms
- What is a Type III Survivorship curve and give an example of an organism who has it?
- Type III: Low Survivorship in early years followed by high survivorship, an example would be an oak tree
- Fecundity
- The number of female offspring produced be each female in the population
- age-specific fecundity
- the average number of female offspring produced by a female in an age class
- age class
- group of individuals of a specific age
- Why is there variation in fecundity and survivorship?
- Every individual has a restricted amount of energy and resources at its disposal causing a difference
- Organisms with high fecundity tend to...
- grow quickly, reach sexual maturity at a young age, and produce mand small eggs or seeds
- Organisms with high survivorship tend to...
- grow slowly and invest resources in traits that reduce damage from enemies and increase their own ability to compete for water, sunlight, or food
- life history
- how an individual allocates resources to growth, reproduction, and activities or structires that are related to survival
- delta N
- change in number of individuals in a population
- population growth
- delta N/delta t
- per-capita rate of increase
- (r) the difference between birth rate and death rate
- intrinsic rate of increase
- (r max) when conditions are optimal-- birth rates are as high as possible and death rates are as low as possible
- density independent
- increases in size of population do not affect r
- density dependent
- increases or decreases in the size of population affect r
- carrying capacity
- (k) as maximum number of individuals in a population that can be supported in a parituclar habitat over a sustained period of time
- logistic growth equation
- delta N/delta t = (r max)(N)((K-N)/K)
- logistic population growth
- changes in growth rate that occur as a function of population size, it is density dependent
- what two general factors change population sizes?
-
density dependent
density independent - density independent factors
- change bith rates and deat rates irrespective of the number of individuals in the population. They are triggered by abiotic factors
- density dependent factors
- usually biotic changes in intensity as a function of population size
- population dynamics
- changes in population through time
- What is the longest running experiment in the history of Biological science?
- the Park Grass study in Rothamsted, UK
- population cycles
- regular fluctuations in the size that some animal populations exhibt
- what is an example of an population cycle
- red grouse (cycle do to transfer of worm when populations started to get crowded)
- age structure
- the proportion of individuals that are at each possible age
- metapopulation
- a population of populations
- zero population growth (ZPG)
- when fertility = replacement rate for a generation
- Migration from nearby populations creates a...
- balance between extinction and recolonization
- population viability analysis (PVA)
- a model that estimates the likelihood that a population will avoid extinction for a given time period.
- What value (%) of a PVA considers a population viable
- 95% of surviving for 100 years
- What is the defining feature of exponential growth?
- the growth rate is constant
- what four factors define population growth?
- death rate, birth rate, immigration, emmigration
- Competition
- -/-
- parasitism
- +/-
- consumption
- +/-
- Mutualism
- +/+
- Commensalism
- +/0
- commensals
- benefit from the association but have no impact on the other species
- coevolutionary arms race
- predator and prey influence each others evolution. Species constantly improving causing other species to improve
- intraspecific competition
- compeition within the same species, major cause of density dependent growth
- interspecific competition
- competition between different species
- niche
- set of habitat requirements, the range of resources that the species is able to use or the range of conditions it can tolerate
- When does interspecific competition occur?
- When the niches of two species overlap
- competitive exclusion principle
- not possilbe for species with the same niche to coexist
- asymmetric competition
- one species suffers a much greater fitness decline than the other species
- symmetric competition
- each species experiences a roughly equal decrease in fitness
- fundamental niche
- niche without predators
- realized niche
- niche when competition occurs
- niche differentiaion
- competing species evolve traits that allow them to exploit different resources or live in different areas
- What are the 6 mechanisms of competition?
- consumptive, preemptive, overgrowth, chemical, territorial, encounter
- Consumptive competition
- two species consume the same resources. (Tree growing in the same area competiting for water and nutrients)
- Preemptive competition
- one species makes space unavailable to others. (Barncles in tidal zone)
- Overgrowth competition
- one organism grows over another. (Fern overgrowing individuals shading them)
- Chemical compeition
- one species produces toxins that negatively affect another. (saliva shurbs)
- territorial competition
- mobile organisms protect a feeding or breeding territory. (Grizzly bears)
- encounter competition
- organisms interfere directly for access to specific resources (hyena and vulture fight over kill)
- What is a common experimental strategy when dealing with competition?
- removing a competitor
- Herbivory:Parasitism::Herbivore:
- Parasite
- standing or constitutive defenses
- defences that are always present
- What are three constitutive defenses?
- schooling, camouflage, and weaponry
- mimicry
- when one species closely resemble another species
- Mullerian mimicry
- when harmful prey resemble each other (posionous toads)
- Batesian mimicry
- harmless species look like harmful prey
- inducible defenses
- defensive traits that are produced only in response to presence of a predator.
- meta-analysis
- a study of studies
- top-down control
- herbivore populatios are limited by predation or disease
- poor-nutrition
- plants are poor food source in terms of the nutrients they provide for herbivores
- plant defense
- plants denfend themselves effectively enough to limith herbivory.
- Not all interaction require individuals from differents species to be...
- nice to each other (altruistic)
- climax community
- the stable final stage after communities develop by passing through a series of predictable stages dictated by extensive interactions among species
- keystone species
- a species with much greater impact than its abundance would suggest.
- disturbance
- any event that removes some individuals or biomass from a commmunity
- What are some examples of disturbances?
- forest fires, hurricanes, floods, fall of large canopy tree, disease epidemcis
- how is the impact of a disturbance determined?
-
1)type of disturbance
2)frequency of disturbance
3)the severity of the disturbance - disturbance regime
- a characteristic type of disturbance with a predictable freequency and severity
- what are the two approaches to determining disturbance regimes?
-
(1) using short term analysis to predict long term patterns
(2) reconstructing history of a particular site - succession
- recovery that follows a disturbance
- primary succession
- occurs when a disturbance removes the soil and its organisms as well as organisms that live above surface
- secondary succession
- occurs when a disturbance removes some or all of the organisms from an area but leaves the soil intact
- successional pathway
- specific sequence of species that appears over time
- What three effects to species have during succession
- facilitation, tolerance, inhibtion
- facilitaion
- promotes growth of other species
- tolerance
- neutral to growth of other species
- inhibtion
- prevents growth of other species
- pionerring species
- first species that arrive after a disturbance, they usually have a high dispersal rate
- species richness
- is a simaple count of how many species are present
- species diversity
- variety of species in a community
- Net primary productivity (NPP)
- is the amount of photosynthesis per unit are per year that ends up in biomass
- resistance
- preventing a disturbance
- resilience
- recovery from a disturbance
- as species richness increases production...
- increases
- What four components are linked by the flow of energy?
- abiotic enviorment, primary producers, consumers, and decomposers
- primary producer
- any organism that can sythesize its own food (autotroph).
- Consumers
- eat other organisms
- Decomposers
- or detritivores are consumers that obtain energy by feeding on the dead remains of other organisms or waste products.
- What place has the highes NPP?
- the ocean
- Why is the ocean produce 25% of the world NPP?
- it takes up such a large area
- primary consumer
- herbivore
- grazing food web
- the collection of animals that eat plants and animals that eat them
- secondary consumers
- consumers that eat herbivores
- decomposer food web
- composed of species that eat the dead remains of organisms
- detritus
- dead animals and dead tissues that accumulate and create plant litter
- trophic level
- organisms that obtain their energy from the same type of source are said to pccupy the same trophic level
- food chain
- connects trophic lebels in a particular ecosystem
- food webs
- shows what each organism eats in a particular ecosystem (more complex than food chain).
- Why are is the equator more diverse than the poles?
- parasite-predator, high productiviy, stability
- gross photosynthetic effciency
- efficiency with which plants use the total amount of energy available to them
- secondary production
- production of new tissue by primary consumers
- Where does most evaporation occur during the global water cycle?
- over the ocean
- What are some effects on the water cycle due to land clearing?
- increase run off, decrease rainfall by decreasing terrestial evaporation
- Why can't carbon be stored sufficently in the ocean?
- Low rate of exchange
- Why are fossil fuels so bad?
- The carbon produced by them can't be getting rid of fast enough creating a green house effect
- What are three human effects on the Nitrogen cycle?
- industrial fertilizers, crop cultivation using N2 fixers, fossil fuel combustion
- In what form does nitrogen have to be in to be used by plants?
- NO3 or NH4
- What are two main areas of human impact?
- Global warming, and productivity increase
- Why is productivity increase bad?
- decreases the species richness and can cause increase in eutrophication
- eutrophication
- the conversion of a lake to a highly productive ecosystem with rapid decomposition, low oxygen levels, and rapid decomposing organic matter
- What is most of the NPP used for in an ecosystem?
- respiration by primary consumers
- biodeversity
- all distinctive populations and species living today
- genetic diversity
- diversity in a parituclar species (allele diversity)
- ecosystem diversity
- variety of ecosystems in a particular region
- direct benefits of biodiversity
- any benefit from when a plant is cultivated
- indirect benefit of biodiversity
- anything beyond the direct use of a species
- ecosystem services
- processes that increase the quality of the abiotic enviorment
- Taxon-specific survey
- estimation of a specific type of organism such as insect living today
- All-Taxon survey
- estimation of all species in a particular ecosystem
- location of largest all-taxon survey
- The Great Smokey Mountains National Park
- endemic species
- taxa that are found nwhere else or a high proportion of endangered species
- What happened on Easter Island?
- resources were overexploited making the island inhabital for organisms
- invasive species
- exotic species that are introduced to a new area
- habitat destruction
- destruction of a habitat by humans
- habitat fragmentation
- fragmenting large areas of natural habitats into small isolated fragments
- What are three problems that can occur when there is an invasive species?
- competition, disease, predation
- domino effect
- endangering one species causes another species to go endangered
- sustainability
- planned use of resources at a rate only as fast as the rate at which they are produced
- NGO
- Nongovernmental Organization
- What are the two conservation strategies?
- in situ, ex situ
- in situ
- protected areas
- ex situ
- zoos, aquaria, and botanical gardens
- sustainable development
- economic progress for local communities
- What does a GAP analysis do?
- compares the current distribution of species with the locations of preserved habitats