NCSU BIO 181 Exam 2 Questions and Answers with complete solution

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, pollutionDemography - 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-curveCharacteristics 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 habitatSemelparity - 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 (+/-)