Download Chapter 5 Review

Biology Populations Chapter 5 Review
name KEY
1) Define population:
__________________________________________________________________
__________________________________________________________________
2) Give an example of a population (note: Be sure to be species specific. “Birds” are not all
members of the same species.)
All of the monarch butterflies in the state of Arizona
3) What factors play a role in population growth rate? Births, deaths, immigration and
emigration
4) What are the 3 characteristics of a population? Geographic distribution, density and growth
rate
5) Define Geographical distribution.
____________________________________________________________________________
6) Define population density.
____________________________________________________________________________
7) Define immigration
__________________________________________________________________
8) Define emigration
__________________________________________________________________
9) If birthrate decreases and deathrate increases, would the population increase, decrease or
stay the same? Population would decrease since less people are being born than dieing.
10) If birth rate increases and death rate increases, would the population increase or decrease
or stay the same? Population would stay the same, since birth and deaths would both be
high.
11) Assuming immigration and emigration are equal, if a population increases, what could be
happening with the birthrate and the deathrate (two different things)?
If a population increases, this means births would be higher than deaths, so the population
could either have A) an increase of birthrate over deathrate, or B) a decrease of deathrate to
below birth rate.
12) Assuming immigration and emigration are equal, if a population decreases what could be
happening with the birthrate and the death rate(two different things)?
If a population decreases, this means births would be lower than deaths, so the population
could either have A) a decrease of birthrate to below the deathrate, or B) an increase of
deathrate to above birth rate.
13) Using immigration and emigration explain how population can increase.
A population can increase by an increase in immigration, over emigration.
14) Using immigration and emigration explain how population can decrease.
A population can decrease by an increase in emigration over immigration.
15) Draw a graph showing exponential growth and label the graph’s axes (with words).
16) Draw a graph showing logistic growth and label the x-axis, y-axis and show the carrying
capacity and label it.
17) What sorts of conditions would lead to a population having exponential growth?
A population can have exponential growth if it has no limit to its resources and no
competition or predation. Usually this would happen at the beginning of a population
arriving in a new location with abundant resources, or in which the local community has no
adaptations to compete with this population. It could also be a population experiencing
regrowth after some sort of disturbance affected the ecosystem.
18) Give an example of a population experiencing exponential growth.
Bacteria newly infecting a body would have exponential growth until the body’s immune
systems would begin to battle with it.
Another example would be a forest regrowth after deforestation.
19) Which graph, logistic or exponential explains most populations? Explain.
Most populations experience logistic growth after an initial period of exponential growth, as
there are almost always limiting factors that come into play.
20) Define carrying capacity
_______________________________________________________________________
_______________________________________________________________________
21) How does carrying capacity affect a population?
Carrying capacity limits the population’s growth from exponential to logistical.
22) Define limiting factors.
_______________________________________________________________________
_______________________________________________________________________
23) Define density dependent limiting factors.
___________________________________________________________________________
___________________________________________________________________________
24) Define density independent limiting factors
___________________________________________________________________________
___________________________________________________________________________
25) Are density dependent limiting factors generally biotic or abiotic? biotic
26) Are density INdependent limiting factors generally biotic or abiotic? abiotic
27) List 2 density dependent limiting factors competition for resources, predation
28) List 2 density independent limiting factors. flood, drought, temperature increase or decrease
29) Explain the relationship between predator and prey and how they affect each other’s
populations.
Predators eat prey, making the prey numbers decrease.
This in turn creates a food shortage for predators,
whose numbers then decrease. This allows prey
populations to rebound, and the cycle continues.
30) What is the limiting factor for the rabbits? Predation by
lynxes
31) What is the limiting factor for the lynxes? Number of
rabbits available for prey
32) In the above graph, are the limiting factors for the rabbits and lynxes density dependent or
density independent? Explain.
The limiting factors are density dependent because they depend on the population density
of both the rabbits and the lynxes.
Graph 1: Rabbits Over Time
33) a. The graph shows a
logistic growth curve.
b. The carrying capacity
for rabbits is
approximately 63
c. During which month
were the rabbits in
exponential growth? May
and the early part of june
Graph 3: Mexico and US
34) In Mexico, what
percentage of the
population is between
0-4 years of age?
Approx 16%
In the US? Approx. 7%
b. Which population is
growing the fastest?
Mexico’s (high
birthrate)
c. Which age group has
the smallest number in
both countries? 80+