Chapter 53 Ecology

Question 1

what is a population

Answer 1

group of individuals of a single species in the same general area

Question 2

how are populations described

Answer 2

by their boundaries and their size

Question 3

what is population ecology

Answer 3

how biotic and abiotic factors affect population density, dispersion, and demogrpahics

Question 4

what is density

Answer 4

of individuals in a particular area

Question 5

what is dispersion

Answer 5

pattern of spacing among individuals within boundaries of a population

Question 6

what is demography

Answer 6

study of birth/death/ migration rates of a population over time

Question 7

is it practical to count all individuals in a poulation

Answer 7

no

Question 8

what do ecologists use to count population

Answer 8

sampling techniques to estimate densities and total populations
or the mark-recapture method

Question 9

what is the mark recapture method

Answer 9

capture, tag and release individuals in a population

Question 10

density is the result of what

Answer 10

interplay between processes that add individuals to a population and those that remove individuals

Question 11

what is immigration

Answer 11

influx of new individuals from other areas

births increase populations

Question 12

what is emigration

Answer 12

the movement of individuals out of a population, and deaths decrease the populaiotn

Question 13

what is the pattern of dispersion determined by

Answer 13

spacing among individuals within the boundaries of a population

Question 14

what can differences in spacing show

Answer 14

biotic and abiotic factors affecting individuals

Question 15

what influences the spacing of indivuals

Answer 15

envirionmental and social factors

Question 16

what are the 3 types of dsitribution

Answer 16

clumped, uniform

Question 17

what is the most common pattern of dispersion

Answer 17

clumped

Question 18

what is ciumped dispersion

Answer 18

individuals aggregate in patches

Question 19

what is an example of clumped dispersion

Answer 19

insects and salamanders are clumped under the same log

Question 20

what can influence clump dispersions

Answer 20

mating behavior and group predation or defense

Question 21

what is a benefit of clumped dispersion

Answer 21

more individuals into groups can increase the effectiveness of predation or defense

Question 22

what is uniform dispersion

Answer 22

evenly spaced, that results from direct interactions between individuals in the population

Question 23

why do animals show uniform dispersion

Answer 23

antagonistic social interactions

Question 24

what is territoriality

Answer 24

the defense of a bounded physical space against encroachment by other individuals

Question 25

what is random dispersion

Answer 25

unpredictable spacing that occurs in the absence of strong attractions or replusions among indivudals or where key physical or chemical factors are relatively constant

Question 26

what is demography

Answer 26

study of key characteristics of populations and how they change over time

Question 27

what is a life table

Answer 27

summarizes the survival and reproductive rates of individuals in specific age-groups within a population

Question 28

what is a cohort

Answer 28

a group of individuals of the same age from birth until all the individuals are dead

Question 29

how do you build the life table

Answer 29

determine the proportion of cohort that survives from one age-group to the next

Question 30

what is a survivorship curve

Answer 30

a plot of the proportion of numbers in a cohort still alive @ that age

Question 31

what is the description of a type 1 survivorship curve

Answer 31

low death rates during early and middle life and a sharp increase in death rates later in life

Question 32

where is type 1 found

Answer 32

in large mammals

Question 33

type 2 curve

Answer 33

constant death rate over organisms life span

Question 34

type 3 species

Answer 34

high death rates for the young and lower death rate for survivors - produce a lot of offspring but can't take care of them

Question 35

what can be used to estimate the number of breeding females

Answer 35

direct counts, mark-recapture, molecular tools like DNA profiling

Question 36

what is the exponential model

Answer 36

describes populaiton in an idealized, unlimited environment

Question 37

what is the equation for population growth

Answer 37

dN/dt = rN | - N: pop size

Question 38

the bigger the rate of constant....

Answer 38

the faster the rate of population

Question 39

why do large populations grow faster than smaller ones

Answer 39

they have more individuals

Question 40

population with larger r....

Answer 40

grows faster than one with smaller r

Question 41

can a population keep growing and growing

Answer 41

no because there won't be a lot of resources

Question 42

what is the logistic population growth

Answer 42

pop growth approaches 0 as the populaiton size nears the carrying capacity

Question 43

what is the equation for the logistics model

Answer 43

dN/dt = rN (K-N/K)

Question 44

what shape does a logistics model have

Answer 44

sigmoid (s-shape)

Question 45

what does life-history comprise

Answer 45

the traits that affect its schedule of reproduction and survival

Question 46

what are the 3 components of an organisms life history

Answer 46

the age, how often the organism reproduces, and how many offspring are produced per reproductive episode

Question 47

the age at first reproduction varies with

Answer 47

the type of species it is