# AP Bio 53

 population a group of individuals of a single species living in the same general area the density of a population is the number of individuals per unit area or volume(aka water living things) Dispersion is the pattern of spacing among individuals within the boundaries of the population what are the 4 ways # of population can change Birth, Death (mortality), Immigration, and emigration (going away) territoriality the defense of a bounded physical space against encroachment by other individuals Demography the study of the vital statistics of populations and how they change over time life tables age-specific summaries of the survival pattern of a population cohort a group of individuals of the same age survivorship curve a graphic method of representing some of the data in a life table. it is a plot of the proportion or number in a cohort still alive at each age reproductive table(fertility schedule) is an age specific summary of the reproductive rates in a population what does N t  ^N and ^t represent population size, time, change in population size, and the time interval over which we are evaluating population growth. what does B and D repreasent births in a population and deaths in a population equation for change in population size in a given time per capita death rate (symbolized by m) and equation an ables us to calculate the expected number of deaths per unit time in a population of any size. D=mN per year per capita birth rate (symbolized by b) and equation the number of offspring produced per unit time by average member of the population. B=bN per year population growth equation using per capita birth and death per capita rate of increase or r r=b-m Zero population growth (ZPG) occurs when the per capita birth and death rates are equal (r=0) exponential population growth  also shown a  or  extra credit question? Which on of the equations above will grow faster? (page 1177) carrying capacity symbolized by K as the maximum population size that a particular environment can sustain logistic population growth model def and equation the per capita rate of increase approaches zero as the carrying capacity is reached   Allee affect (named after W.C. Allee of the University of Chicago who first described it) in which individuals may have a more difficalt time surviving or reproducing if the population size is too small life history def the traits that affect an organism's schedule of reproduction and survival life history's 3 main variables when reproduction begins, how often the organism reproduces, and how many offspring are produced per reproductive epsiode semelparity "one-shot" pattern of big-bang reproduction examples of speacies that do this is the Pacific salmon and seasonal plants iteroparity repeated reproduction aka US this spiecise tipicaly care for their young  K-selection selection traits that are sensitive to population density and are favored at high densities or density-dependent (close to carrying capasity) r-selection selection for traits that maximize reproductive success in uncrowded environments or density-independent (below carrying capacity) density independent a birth rate or death rate that does NOT change with population size or density density dependent a death rate that rises as population density rises as is a birth rate that falls with rising density  Mechanisms of Density Depedent regulations see page 1183 cause i'm lazy  population dynamics population fluctuations from year to year or place to place are influenced by many factors and in turn affect other species including our own demographic transition the movement from high birth and death rates toward low birth and death rates Authordoctorwhogirl998 ID169445 Card SetAP Bio 53 DescriptionAP Bio chapter 53 Updated2012-09-08T16:25:17Z Show Answers