Characteristics of Characteristics of The BiosphereThe Biosphere

Carrying capacity- Carrying capacity- largest number of largest number of individuals an individuals an environment can environment can support and support and maintainmaintain

Lag Phase- period Lag Phase- period of slow growth in a of slow growth in a populationpopulation

Exponential Growth Exponential Growth Phase- population Phase- population repeatedly doubles repeatedly doubles in a specific timein a specific time

Stabilization Phase- Stabilization Phase- deaths are equal to deaths are equal to births, no growthbirths, no growth

Population size: Population size: the number of the number of individuals in individuals in populationpopulation

Population density- Population density- the number of the number of individuals in a individuals in a given area given area

Biotic potential- Biotic potential- number of number of individuals that individuals that each female in a each female in a population can population can produce under the produce under the best possible best possible conditions (food, conditions (food, water shelter etc.)water shelter etc.)

J curveJ curve

Shows a Shows a population that is population that is still in the still in the exponential exponential growth phasegrowth phase

S- CurveS- Curve

Population grows Population grows slowly at first, then slowly at first, then enters rapid enters rapid growth and finally growth and finally stabilizesstabilizes

At that point the At that point the carrying capacity carrying capacity of that of that environment has environment has been achievedbeen achieved

Saw-tooth or Saw-tooth or Predator/Prey curvePredator/Prey curve

Predation- the Predation- the feeding of one feeding of one organism on organism on anotheranother

The population of The population of one species directly one species directly affects the affects the population of the population of the other speciesother species

Limiting FactorsLimiting Factors

Density-Density-dependent: Any dependent: Any factor that factor that directly limits the directly limits the size of the size of the populationpopulation

Examples: Food, Examples: Food, water, shelter, water, shelter, spacespace

Density-Density-independent: independent: factors that affect factors that affect all populations in all populations in the same way the same way regardless of the regardless of the population densitypopulation density

Example: Climate, Example: Climate, fire, floodfire, flood

Population EquationsPopulation Equations

Birth Rate: births/total pop. x 100Birth Rate: births/total pop. x 100 Death Rate: deaths/total pop. X 100Death Rate: deaths/total pop. X 100 Population Change: Population Change:

(births + immigrants) – (deaths + (births + immigrants) – (deaths + emmigrants) =emmigrants) =

Growth Rate: pop. change/total pop. Growth Rate: pop. change/total pop. x100x100

The SymbiosisThe Symbiosis

M u tu a lism C om m en sa lism P aras it ism

S ym b ios isre la tion sh ip in w h ich tw o d iffe ren t o rg an ism s live in c lose assoc ia tion

MutualismMutualism A relationship in which A relationship in which

two species interact two species interact closely in a way that closely in a way that benefits both speciesbenefits both species

Ex: butterfly and Ex: butterfly and flowerflower

Butterfly gets food Butterfly gets food from flowerfrom flower

Flower disperses Flower disperses pollen via the butterflypollen via the butterfly

CommensalismCommensalism Relationship in which Relationship in which

one organism benefits one organism benefits from the interaction, from the interaction, and the other is neither and the other is neither helped nor harmedhelped nor harmed

Ex: barnacles and Ex: barnacles and whaleswhales

Barnacles move from Barnacles move from place to place via place to place via whalewhale

Whale not affectedWhale not affected

ParasitismParasitism Relationship between two Relationship between two

organisms in which one organisms in which one species (parasite) harms species (parasite) harms the other species (host)the other species (host)

Ex: ticks and mammalsEx: ticks and mammals Ticks live under the skin Ticks live under the skin

of mammals and suck of mammals and suck blood and nutrients from blood and nutrients from mammalmammal-tick will not kill its host -tick will not kill its host because it needs it as a because it needs it as a resourceresource-Mammal is severely -Mammal is severely weakened and harmed weakened and harmed but does not diebut does not die