NCSU BIO 181 Exam 2 With Complete Solutions.

What is ecology? - ANSWER the study of how organisms interact with each other and with their environment What are the 5 areas of ecological study? - ANSWER -Organismal: study of physiological, evolutionary, and behavioral mechanisms used by individual organisms to meet ecological needs -Population: how populations interact with their environment, how and why the # of individuals changes over time, the proportion of males to females, age of individuals, how likely they are to reproduce or die (Characteristics: range, spacing pattern, changes in size over time) -Community: Interacting populations of same and different species living within a given area -Ecosystem: study of changes in the community in response to changes in abiotic components of the ecosystems -Landscape: study of energy and matter (including organisms) exchanges between ecosystems Name abiotic factors. (5) - ANSWER Sunlight, temperature, rainfall (water), soil conditions, geography Biotic factors - ANSWER living portion (animals, plants, decomposers, etc) What is a population? - ANSWER A group of individuals of the same species inhabiting the same area Name density-dependent factors. - ANSWER Disease, competition, predation, parasitism, competition for resources Interspecific competition - ANSWER different species competing for the same resources Intraspecific competition - ANSWER the same species competing for the same resources Name density-independent factors. - ANSWER drought, freezes, floods, habitat loss, forest fires, storms, pollution Demography - ANSWER -the study of factors that determine the size & structure of populations through time -Age structure, or the relative number of individuals of each age. -How likely individuals are to survive the following year -How many offspring are produced by females of different ages -How many individuals of different ages immigrate and emigrate each generation Population growth - ANSWER the change in the number of individuals in the population (∆N) per unit time (∆t) Population Dynamics - ANSWER Interaction of all of the above factors What is r defined as? - ANSWER -Growth rate/ per capita rate of increase -Positive r= population is growing -Negative r=population is declining -r=0 zero population growth (ZPG) When does exponential growth occur? - ANSWER -Colonizing new habitats -Recovering What type of curve shows exponential growth? - ANSWER J-curve What is a carrying capacity (K)? - ANSWER The maximum number of individuals in a population that can be supported by a particular habitat over a period of time What is the logistic curve equation? - ANSWER ∆N/∆t=rN(K - N)/K (Describes the proportion of unused resources and space in the habitat) What type of curve shows logistic growth? - ANSWER S-curve Characteristics of r-selected species? - ANSWER reproduces early, short life span, short maturation time, high mortality, large litters, few numbers of reproductions per lifetime, no parental care, small offspring Characteristics of K-selected species? - ANSWER reproduces late, long life span, long maturation time, low mortality, small litters, larger numbers of reproductions per lifetime, parental care, large offspring Fecundity/Age-Specific Fertility (mx) - ANSWER number of offspring per surviving female of age class "x": (offspring produced at age class "x") / nx Net reproductive rate (R0) - ANSWER sum of lxmx Cohort - ANSWER all individuals of the same age Type I Survivorship - ANSWER K-selected species (late mortality) Type II Survivorship - ANSWER uniform rate of decline Type III Survivorship - ANSWER r-selected species (early morality) Dispersion Patterns- Clumped Spacing - ANSWER Most common, resources tend to be clustered in nature, social behavior may promote this pattern Uniform spacing - ANSWER Competition may cause this pattern, may also result from social interactions Random Spacing - ANSWER Rarest, resources are rarely randomly spaced, may occur where resources are common and abundant Metapopulation - ANSWER Occur in areas in which suitable habitat is patchily distributed and is separated by intervening stretches of unsuitable habitat Semelparity - ANSWER produce all offspring in a single reproductive event, individuals reproduce once and die Iteroparity - ANSWER reproduce in successive years or breeding seasons Seasonal Iteroparity - ANSWER distinct breeding seasons Continuous Interoparity - ANSWER reproduce repeatedly at any time of the year Ecological Footprint - ANSWER Aggregate of land needed for survival in a sustainable world Resource Competition - ANSWER organisms compete indirectly through the consumption of a limited resource Interference Competition - ANSWER individuals interact directly with one another by physical force or intimidation Ecological Niche - ANSWER the sum total of a species' use of the biotic and abiotic resources in its environment Resource Partitioning - ANSWER when similar species exploit the limited resources in an ecological area without one species driving the others into extinction Character Displacement - ANSWER when natural selection favors those individuals in each species that compete least with individuals of the other species (Species evolve to be different from one another) Allopatric populations - ANSWER closely related species that are geographically separate Sympatric populations - ANSWER closely related species that are geographically overlapping Predation - ANSWER When a predator species kills a prey species and consumes most or all of it (+/-) Predator feeding adaptations - ANSWER claws, fangs, teeth, stingers, poison Green World Hypothesis - ANSWER Terrestrial herbivores consume less than 17% of the total net primary production by plants Batesian Mimicry - ANSWER Harmless species looks like predator Mullerian Mimicry - ANSWER 2+ harmful species look like one another Cryptic Coloration - ANSWER camouflage Disruptive Coloration - ANSWER Blend together, makes it hard for predator to differentiate between them (Herd of zebras) Aposematic Coloration - ANSWER warns or danger Other prey defenses - ANSWER schooling, intimidation, weaponry Symbiosis - ANSWER Two organisms living in direct contact with each other for a brief or long period of time Mutualism - ANSWER +/+ Commensalism - ANSWER +/0 Parasitism - ANSWER benefits one (symbiont), harms the other (host) (+/-) Endoparasite - ANSWER lives inside host Ectoparasite - ANSWER lives on host Parasitoidism - ANSWER deposits eggs on or in host Endosymbiont - ANSWER organisms live inside one another Phoresy - ANSWER One organism rides on another Coevolution - ANSWER where two (or more) species reciprocally affect each other's evolution Species richness - ANSWER the total number of different species Relative Abundance - ANSWER the proportion each species represents Dominant Species - ANSWER the most abundant Keystone Species - ANSWER the most influential Foundation Species - ANSWER one that allows other species to inhabit a given area by altering the environment Intermediate disturbance hypothesis - ANSWER moderate disturbances can create opportunities for greater species diversity Primary Succession - ANSWER Begins in an almost lifeless area where soil has been removed by volcanic eruptions, glaciers, floods, or landslides Secondary Succession - ANSWER Begins in areas where a disturbance removes some or all of the organisms but leaves the soil intact, e.g, fires, logging Facilitation - ANSWER early stages; promotes other species by improving area Tolerance - ANSWER does not hinder or promote Inhibition - ANSWER some species prevent others Ecosystem - ANSWER A system of multiple communities along with their chemical and physical environments Decomposers - ANSWER Transfer chemical elements back to soil, water, air, prokaryotes and fungi, active at all trophic levels Trophic Structure - ANSWER Feeding relationships between organisms Food chain - ANSWER transfer of food energy through the trophic levels Energetic h