Download Population Dynamics #3: Symbiotic Relationships and Life Strategies

Biology 30 Reading Notes
Section 20.1
Pages 704 - 715
Name:____________________
POPULATION GROWTH
 ____________ density is defined as the number of ______________
organisms in a given __________ or ________.
Give the equation of population density:
DISTRIBUTION PATTERNS
 Distribution patterns are influenced by the distribution of ___________ in
a habitat and the ______________ among members of a ___________
or members of a _____________.
 __________ distribution in a habitat is characterized by individuals or
pairs of organisms distributed throughout a ____________ habitat with
__________ identifiable pattern. It occurs when resources are
____________ and members of a population _________ have to
compete with one another or group together for survival. Random
distribution in nature is rare. An example is the summer population of
individual bull moose and female moose (Alces alces) with calves.
 In __________ distribution, members of a population are found in
groups within their habitat. Most populations exhibit a __________
pattern of distribution, congregating in an area where ___________,
_____________, or ___________ is most abundant.
 Members of the population are grouped together for _____________
and ____________ scarce resources.
 Examples of clumped distribution cited in the text are humans,
____________ (Populus tremuloides), and the ___________ (Physella
johnsoni.)
 In uniform distribution, members of a species are ____________ spaced
over a habitat. The members __________ direct competition over
resources by ____________ up the territory. Examples of this pattern
are ______________ and other organisms that how territoriality to
________________ their resources and protect their ______________.
The golden eagle (Aquila chrysaetos) is a specific example of a species
exhibiting uniform distribution.
POPULATION GROWTH
 The four processes that affect population size are __________(b),
_______________ (i), __________ (d), and _________ (e).
Give the change in population growth formula:
 _________________ ____________ ____________ (gr) refers to the
change in population size (_N) over a specific time frame (_t).
 The ________ __________ growth rate (cgr) takes into account the
____________ size of the population and is determined by calculating
the __________ in population size (_N) during a given time interval (_t),
and then dividing the change in population size by the _____________
_____________ of individuals in the population (N).
FACTORS THAT AFFECT POPULATION GROWTH
 The __________ ______________ (r) of a population is its highest
possible ________________________ rate.
 Four factors that determine the _________ potential of a species are
(1) the ___________ of offspring per __________ cycle;
(2) the _____________ of offspring that survive long enough to
_____________;
(3) the __________ of reproductive maturity and the ___________ of
times that the individuals reproduce in a ____________; and
(4) the life span of the ___________.
 An _____________ growth pattern is a growth pattern that begins with a
brief _________ phase (slower growth), followed by much more
___________ growth as the number of _____________ capable of
reproducing continues to _____________.
 This type of growth pattern has a _____________ curve on a line graph.
 A population growing at its ______________ potential would be
expected to follow an ______________ growth pattern.
 In the beginning, the growth of a small population is __________
since only a ________ individuals ___________. The small initial
population constitutes the “_____ phase,” shown by a gentle
___________ in the curve.
 As __________ organisms reproduce, the population will grow in
greater and greater ___________, exhibited by a ___________
increase in the growth curve. Because the __________ rate during
this phase of _____________ growth is much greater than the
____________ rate, the population size ____________ rapidly.
CARRYING CAPACITY
 ____________________ (K) is the theoretical _____________
population size that an environment can sustain over an extended
period of time. It represents the number of _________________ in a
population that can live in a given _______________ without depleting
the _____________ they need or harming their habitat or ___________.
 Density-__________ factors are ____________; that is, they are directly
related to __________ organisms.
 These factors have a greater impact when population density is
_________.
 Examples of density-dependent factors include ___________
and ___________ (which spread more rapidly in a dense
population),
 scarcity of __________ due to intense _____________, and
increased predation, since a dense population means there is
an abundance of ________ for ____________.
 Density-______________ factors, which are ___________ and
_________ the growth of a population, regardless of its size or
__________.
 They include extreme __________, drought, _____________,
forest fires, and destruction of ____________ through
_____________ intervention.
 _____________________ __________________ to population growth
refers to the combined effects of interacting ______________ factors.
 Environmental resistance ____________ a population from growing
to its biotic potential and determines the ___________
_____________ of the habitat.
LIFE STRATEGIES
____________-selected life strategies
live close to their _________ potential
_____________ offspring per reproductive cycle
offspring receive _________ or no _____________ care
__________ life span
early ________________ age
_________________ on favourable ________________ conditions
_____________-selected life strategies
live close to the ___________ ____________ of their environment
_________ offspring per reproductive cycle
one or both ___________ care for their young
_________ life span
_________ reproductive age
_________ dependent on favourable _______________ conditions