BIOL 215 Final Exam UPDATED ACTUAL
Exam Questions and CORRECT Answers
What is ecology? - CORRECT ANSWER - considers how orgs interact w/their
environment, individuals in same species/other species, to affect their abundance and distribution
and reproduction
Population as a unit of study - CORRECT ANSWER - a population is a group of
organisms of the same species occupying a particular space at a particular time
unitary or modular individuals - CORRECT ANSWER - typical population made up of
unitary individuals; modular produced by zygote, zygote grows into young individual (imagine
grass seed, grows into grass, shoots/roots go onto make new grass)
density - CORRECT ANSWER - size is inversely related, smaller animals more abundant
than larger
quadrats for sessile organisms - CORRECT ANSWER - for sessile organisms; small
sampling device of known area, usually in square/rectangle shape (can be any shape) position
randomly in environment; need to replicate to get estimate of variants, standard deviation, etc;
determine number of individuals /area and scale to larger area
capture-recapture method - CORRECT ANSWER - for mobile organisms; ex, look at lake
w/goldfish pop, capture some goldfish, tag them in way that doesn't influence behavior, come
back later and capture more fish, some tagged some not, use ratio of marked fish to total fish
caught in 2nd sample to calculate total pop size
factors that influence population size - CORRECT ANSWER - natality (births and
immigration), mortality (deaths and emigration)
Demographic techniques - CORRECT ANSWER - quantitative methods to assess changes
in population size (due to mortality/natality), immigration and emigration are important but
harder to study
,life table - CORRECT ANSWER - a table that records survivorship (hence mortality) in a
population; if we combine a life table w/a fertility table, can make estimates of how population
grows
2 ways to make a life table - CORRECT ANSWER - cohort table and static table
cohort table - CORRECT ANSWER - follows all individuals born at the same time from
birth to death; most difficult but the best method
static table - CORRECT ANSWER - Snapshot of a population over a short time interval;
Individuals are of different ages; for organisms with long generation times (humans/elephants)
Dall sheep study - CORRECT ANSWER - Murie collected sheep skulls and aged them,
used the data to construct a life table and survivorship curve; assumed that proportion of skulls in
each age class represented typical proportion of individuals dying at that age, and that pop size,
birth/death rates in each group stayed constant; concluded mortality mostly due to old age,
debunked idea that wolves were limiting/restricting pop size
estimates of reproductive rate - CORRECT ANSWER - life table can also be used to
derive estimates of reproductive rate of pop; estimate how pop will change; useful when info
can't be readily gathered (long lived, slow growing pops); to estimate reproductive rates of pop
keep track of females
calculate net reproductive rate - CORRECT ANSWER - R0 = #daughters produced/female
during lifetime; sum of survivorship and reproduction for each age class
calculate generation time - CORRECT ANSWER - mean time period between
production/birth of parents and production/birth of offspring (∑xLxBx)/R0
calculating intrinsic capacity for increase (r) - CORRECT ANSWER - step 1: calculate net
reproductive rate
, step 2: generation time
step 3: calculate intrinsic capacity for increase
parameter of interest (r) - CORRECT ANSWER - r is the per capita rate of increase in the
exponential model (r = dN/dt); it also equals instantaneous birth per capita birth rate -
instantaneous per capita death rate; when r = 0, growth = 0
r increases ... - CORRECT ANSWER - 1. as age at first reproduction decreases
2. as number of progeny per reproductive event increases
3. as number of reproductive events increases
why measure r? - CORRECT ANSWER - determine whether a pop is growing, declining,
or staying constant; sensitive to environmental change that ecologists might not detect; predict
pop density in future
using r to predict population abundance at some point in the future - CORRECT
ANSWER - Nt = (N0)e^rt
populations with discrete generations - CORRECT ANSWER - single annual breeding
seasons; describe growth using exponential growth equations; b/c have discrete generations,
generation time is 1 year; pops don't usually grow this way in nature
populations grow exponentially - CORRECT ANSWER - at initial stages of colonization,
when conditions are favorable, and sometimes when recovering from negative environmental
perturbation; natural populations can't sustain forever
Growth of populations w/overlapping generations and continuous breeding - CORRECT
ANSWER - r is not remaining constant; sometimes you have pop decline, other pop
increases, other staying stable; measurements of r only pertain to particular instance in time, can't
be used to predict pop growth over long timescales
Exam Questions and CORRECT Answers
What is ecology? - CORRECT ANSWER - considers how orgs interact w/their
environment, individuals in same species/other species, to affect their abundance and distribution
and reproduction
Population as a unit of study - CORRECT ANSWER - a population is a group of
organisms of the same species occupying a particular space at a particular time
unitary or modular individuals - CORRECT ANSWER - typical population made up of
unitary individuals; modular produced by zygote, zygote grows into young individual (imagine
grass seed, grows into grass, shoots/roots go onto make new grass)
density - CORRECT ANSWER - size is inversely related, smaller animals more abundant
than larger
quadrats for sessile organisms - CORRECT ANSWER - for sessile organisms; small
sampling device of known area, usually in square/rectangle shape (can be any shape) position
randomly in environment; need to replicate to get estimate of variants, standard deviation, etc;
determine number of individuals /area and scale to larger area
capture-recapture method - CORRECT ANSWER - for mobile organisms; ex, look at lake
w/goldfish pop, capture some goldfish, tag them in way that doesn't influence behavior, come
back later and capture more fish, some tagged some not, use ratio of marked fish to total fish
caught in 2nd sample to calculate total pop size
factors that influence population size - CORRECT ANSWER - natality (births and
immigration), mortality (deaths and emigration)
Demographic techniques - CORRECT ANSWER - quantitative methods to assess changes
in population size (due to mortality/natality), immigration and emigration are important but
harder to study
,life table - CORRECT ANSWER - a table that records survivorship (hence mortality) in a
population; if we combine a life table w/a fertility table, can make estimates of how population
grows
2 ways to make a life table - CORRECT ANSWER - cohort table and static table
cohort table - CORRECT ANSWER - follows all individuals born at the same time from
birth to death; most difficult but the best method
static table - CORRECT ANSWER - Snapshot of a population over a short time interval;
Individuals are of different ages; for organisms with long generation times (humans/elephants)
Dall sheep study - CORRECT ANSWER - Murie collected sheep skulls and aged them,
used the data to construct a life table and survivorship curve; assumed that proportion of skulls in
each age class represented typical proportion of individuals dying at that age, and that pop size,
birth/death rates in each group stayed constant; concluded mortality mostly due to old age,
debunked idea that wolves were limiting/restricting pop size
estimates of reproductive rate - CORRECT ANSWER - life table can also be used to
derive estimates of reproductive rate of pop; estimate how pop will change; useful when info
can't be readily gathered (long lived, slow growing pops); to estimate reproductive rates of pop
keep track of females
calculate net reproductive rate - CORRECT ANSWER - R0 = #daughters produced/female
during lifetime; sum of survivorship and reproduction for each age class
calculate generation time - CORRECT ANSWER - mean time period between
production/birth of parents and production/birth of offspring (∑xLxBx)/R0
calculating intrinsic capacity for increase (r) - CORRECT ANSWER - step 1: calculate net
reproductive rate
, step 2: generation time
step 3: calculate intrinsic capacity for increase
parameter of interest (r) - CORRECT ANSWER - r is the per capita rate of increase in the
exponential model (r = dN/dt); it also equals instantaneous birth per capita birth rate -
instantaneous per capita death rate; when r = 0, growth = 0
r increases ... - CORRECT ANSWER - 1. as age at first reproduction decreases
2. as number of progeny per reproductive event increases
3. as number of reproductive events increases
why measure r? - CORRECT ANSWER - determine whether a pop is growing, declining,
or staying constant; sensitive to environmental change that ecologists might not detect; predict
pop density in future
using r to predict population abundance at some point in the future - CORRECT
ANSWER - Nt = (N0)e^rt
populations with discrete generations - CORRECT ANSWER - single annual breeding
seasons; describe growth using exponential growth equations; b/c have discrete generations,
generation time is 1 year; pops don't usually grow this way in nature
populations grow exponentially - CORRECT ANSWER - at initial stages of colonization,
when conditions are favorable, and sometimes when recovering from negative environmental
perturbation; natural populations can't sustain forever
Growth of populations w/overlapping generations and continuous breeding - CORRECT
ANSWER - r is not remaining constant; sometimes you have pop decline, other pop
increases, other staying stable; measurements of r only pertain to particular instance in time, can't
be used to predict pop growth over long timescales
