Knowledge in population

Population structure

Population refers to the individuals living or inhabiting in the same area at the same time.Its dynamics depends upon age,density,dispersion,size & speciation. Factors of population: 1.Natality:no. of individuals added through birth. 2.Mortality:no. of individuals removed through death. Population density:no. of individuals in a population per unit habit area.It depends on structure ,age & mating. A speciation in a population dynamics involves generation or formation of new species through evolution that may occur in a particular geographical area. Types of speciation: 1.Sympatric:When new & existing species live in same geographical area at same time period. 2.Allopatric:When different species live in diiferent geographical ares but at same period of time. 3.Parapatric:Addition of new species to a new geographical area which may lead to positive & negative interactions between population groups which may lead to deletion of a few selected species. Population dispersion can be in the form of cluster,clump,uniform or random. Fluctuation in a population may occur due to environmental changes. Population studies are represented as demographs,Its a graphical way of representing population statics,they are usually related to  a no. of 1000 or more.They can be in the form of stable,expanding or declining structure. Population growth depends on biotic & abiotic factors,they are charachterised as both generalised & logical.In generalised form there are four phases such the lag phase which is the early growth phase,log phase which is the exponential phase,stationary or stable phase & declining or death phase.In logical form,it is assumed that more  no. of population are found in that particular period of time. Survivalship curve refers to an organisms adapatation & its ability to reproduce naturally under a given duration of time which later on represented in the form of a graph. Factors influencing population growth are natural calamities,birth & death rate,increased predation,competetion for food & other resources & disease.  

Population and Growth

Population and its growth notes for environmental studies

Organisms and population

the pdf contains information about organisms and population. the notes are helpful for neet