CAMPBELL BIOLOGY CHAPTER 53 QUESTIONS AND ANSWERS

CAMPBELL BIOLOGY CHAPTER 53 QUESTIONS AND ANSWERS population - answer- a group of individuals of a single species living in the same general area, rely on the same sources and breed with one another, described by boundaries and size density - answer- number of individuals per unit of area or volume dispersion - answer- pattern of spacing among individuals within the boundaries of the population mark-recapture method - answer- estimate the size of wildlife populations by marking and releasing animals and then recapturing them immigration - answer- influx of new individuals from other areas (birth) emigration - answer- movement of individuals out of a population and into other locations (death) clumped dispersion - answer- individuals aggregated in patches, associated with better environmental conditions, mating behavior, increase effectiveness of defense uniform dispersion - answer- evenly spaced resulting from direct interactions between individuals territoriality - answer- result from uniform dispersion, defense of a bounded physical space random dispersion - answer- position independent of other individuals, no strong connections or repulsions demography - answer- study of the vital statistics of populations and how they change over time (death and birth rates) life tables - answer- age-specific summaries of the survival pattern of a population cohort - answer- group of individuals of the same age, from birth until all of the individuals are dead Survivorship curve - answer- plot of the proportion or numbers in a cohort still alive at each stage Type I - answer- flat at start, reflecting low death rates during early and middle life, drops steeply as death rates increase among older age groups (humans) Type III - answer- drops sharply at the beginning, but flattens out as death rates decline (fish) Type II - answer- constant death rate (squirrel) reproductive rate - answer- how reproductive output varies with the ages of females reproductive table - answer- age specific summary of the reproductive rates in a population, measures the reproductive output of a cohort from birth to death reproductive output - answer- product of the proportion of female offspring of those breeding females Exponential population model - answer- population growth in an ideal unlimited environment, J-shaped curve per capita birth rate - answer- number of offspring produced per unit of time by an average member of the population B=bn per capita death rate - answer- expected number of deaths per unit of time D=mn zero population growth - answer- balance of birth and death rates r=0 carrying capacity - answer- (K), maximum population size that a particular environment can sustain Logistic population model - answer- per capita rate of increase approaches zero as the carrying capacity is reached, S-shaped curve, limited resources allele effect - answer- individuals may have a more difficult time reproducing if the population size is too small life history - answer- traits that affect an organism's schedule of reproduction and survival, 3 variables: when reproduction begins, how often the organism reproduces, how many of offspring are produced per reproductive cycle semelparity - answer- big-bang reproduction, produces offspring in ideal conditions and then die, favored in environments that are variable and unpredictable iteroparity - answer- repeated reproduction, generally produce few but large organisms and take care of them better, favored in environments that are dependable k-selection - answer- selection for traits are are sensitive to population density, favored at high densities, density dependent, populations near K r-selection - answer- selection for traits that maximize reproductive success in uncrowded environments, maximize per capita rate of increase density independe