Adapted from L. Miriello by S. Sharp
AP Biology
Chapter 52 Guided Reading
Name __________________________
1. Define the following terms:
a. Population: group of individuals of single species living in same general
area
i. Influenced by similar environmental factors
ii. Same resources
iii. Likely to breed together
iv. No population can grow indefinitely
b. Density: # of individuals per unit area or volume
i. Not a static property
ii. Variations in local density = most important thing studied related to
pop.
c. Dispersion: pattern of spacing among individuals w/in boundaries of pop.
d. Mark-recapture method: sampling technique used to estimate wildlife pop.
i. Animals are trapped and marked so data can be collected from
them
e. Immigration: influx of new individuals from other areas; contribute to
density
f. Emigration: the movement of individuals out of a pop.; contributes to
density
g. Territoriality: the defense of a bounded physical space against
encroachment by other individuals
2. What are the three patterns of dispersion and what conclusions can you draw from
these patterns?
#1 clumped: individuals aggregated in patches; plants, fungi, salamanders, forest
insects where germination is favored or microenvironment satisfies requirement
(ex. Clumping under a log)
a. pack of wolves
#2 uniform: evenly spaced pattern of dispersion resulting from direct interaction b/w
individuals
a. king penguins nesting on small island
#3 Random: unpredictable spacing; occurs in absence of strong attractions or
repulsions among individuals
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Adapted from L. Miriello by S. Sharp
a. dandelions in field
3. Define the following terms:
a. Demography: study of the vital statistics of populations as they change
over time
b. Life tables: age specific summaries of the survival pattern of a pop.
i. Needed to estimate how long individuals expected to live
ii. study a cohort: group of individuals of the same age from birth until
death
c. Survivorship curves: a plot of the proportion or numbers in a cohort still
alive at each age
d. Reproductive table: fertility schedule, age specific summary of the
reproductive rates of a pop.
i. Concentrates on the females b/c theyre the ones reproducing
ii. Particular type of reproductive pattern for each species so table
looks different accordingly
e. Life history: the traits that affect an organisms schedule of reproduction
and survival
4. Use the diagram below – label the three different survivorship curves – give an
example of an animal that fits the curve and an explanation of why they fit the curve.
Type 1: humans or mammals that produce few offspring: low death rates, then rates
increase due to old age
Type2: squirrels, rodents, lizards, annual plants: constant death rate
Type 3: long lived plants, fish, marine invertebretes who produce many offspring and
provide little care: high death rates when young, flattens out as death rates decrease
for those who survived a certain critical age
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Adapted from L. Miriello by S. Sharp
5. Compare and contrast semelparity and iteroparity – give advantages of each as
they apply to an example organism – focus on the adaptive benefit of the life history.
Are there any disadvantages? This is a core concept.
- semelparity/ big-bang reproduction: a life history in which adults have but a single
reproductive opportunity to produce large #s of offspring
(+) agave plants adapt to erratic climate by storing up nutrients for reproduction
and when time is right releasing everything for best shot at reproducing
(+) when survival rate of offspring is low
- repeated reproduction/ iteroparity: life history in which adults produce large #s of
offspring over many years
(+) favored in more dependable environments when a few, strong offspring are
produced; therefore can survive better when born into intense competing environment
6. What is zero population growth?
When per capita birth and death rates are equal (r=0, r= per capita rate of increase)
7. What is exponential population growth? What kind of graph would you expect to
see?
The geometric increase of a pop. As it grows in an ideal, unlimited environment
-the per capita rate of increase may assume the max rate for a species = intrinsic
rate of increase
- j shaped growth curve
8. Read section 52.4 slowly – we are not focusing on all of the math but the concepts –
explain the logistical population growth model. Studying the graph below – what does it
tell you and why? How does “K” fit in to all of this?
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Adapted from L. Miriello by S. Sharp
- logistic growth model = per capita rate of increase declines as carrying
capacity is reached
- k = the carrying capacity
9. Compare and contrast r and k selection – this is a key concept – do some additional
research and try to come up with at lease six points of comparison.
- r selection: density independent selection; selection for life history traits that
maximize reproductive success in uncrowded (low density) environments
- tends to maximize rate of increase and occurs in environments in which pop.
Density well below carrying capacity or little competiton
-k selection: density dependent selection; selection for life history traits that are
sensitive to pop. Density
- tends to maximize pop. Sizes and operated in pop. Living in density near limit
* different populations of a species may have different balance of traits from these 2
selections
10. What is the difference between density-dependent and density-independent factors
as a general term?
- density independent: a birth or death rate that doesn’t change w. population density
- density dependent: death rate that rises as pop. Density rises or as birth rate falls with
rising density
11. What generalizations can be made by the graphs below?
a) birth & death rate change w/ pop. density
b) birth rate change w/ density while death rate is constant
c) death rate changes w/ density while birth rate is constant
12. Describe six density-dependent factors in population regulation.
#1 competition for resources: increasing pop., decreasing amount of nutrients and
resources available
#2 territoriality: may limit density b/c territory is a limited resource
#3 Health: pop. Density influences health & thus survival of organisms
#4 predation: if prey pop. Increases, predators may feed preferentially off of that
species, therefore consume a higher percentage of them
#5 toxic wastes: as pop. Grows, toxins can accumulate, poisoning pop.
#6 intrinsic factors: ex. High pop. Density can cause aggressive behavior in some
species, decreases reproduction success
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Adapted from L. Miriello by S. Sharp
15. What is population dynamics?
-focuses on complex interactions b/w biotic & abiotic factors that cause variation in pop.
Size
16. Describe human population growth after studying figures 52.22 and 52.23.
- populations continues to grow each day BUT the rate of growth is slowing
17. What kinds of information do age structure pyramids provide and what inferences
can be made from these?
- age structure: the relative # of individuals of each age
* predict a populations growth trend
*illuminate social conditions
18. How can an ecological footprint be useful?
-ecological footprint = concept summarizes the aggregate land and water area
appropriated by each nation to produce all the resources it consumes and to absorb all
the waste it generates
-estimates the amount of resources were using, gives ability to compare to other
countries, easy to predict the future and availability of resources based on the amount
being used in the present day
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