Download 2. Population Biology Sheet

Name: _________________________________________ Date: __________ Period: __________
Population Biology
Key Terms and Definitions
1. Population Density: the number of individuals per unit area
a. In each box, draw a picture to illustrate the description provided.
Low Population Density
High Population Density
b. If the density of an animal population in the wild becomes too high, what problems can
result?
c. If the density of a human population in a city gets too high, what problems can result?
2. What factors can cause the size of a population to change? Define the terms and state
whether each causes an increase or decrease in the population.
a. Birth
b. Death
c. Emigration
d. Immigration
e. Disease
f. Competition
3. Exponential Growth—Growth of populations in which the population doubles with every round
of reproduction.
a. In good conditions, bacterial cells divide every 20 minutes. If you start with one
bacterial cell, how many cells would you have after:
i. 20 minutes: ____________
ii. 40 minutes: ____________
iii. 60 minutes: ____________
iv. 120 minutes: ____________
v. 240 minutes: ____________
vi. 1 day: ____________
b. Consider bacteria growing in a petri dish. Will this bacteria population continue to
increase forever? Why or why not?
c. What are some factors that prevent the human population from increasing?
d. Gray Wolf Population in Wisconsin
1985
1990
1995
2000
2005
Years
2010
2015
2020
4. Between what years does the population growth of the gray wolf in Wisconsin appear to be
exponential?
5. What will happen to the rate at which the gray wolf population increases after the year
2010?
6. Why will the rate at which the gray wolf population increases after the year 2010 slow
down?
7. What term describes the maximum population size that can be supported by a single
environment?
8. What type of growth occurs when a population’s growth slows or stops following a period of
exponential growth?
9. In 1900 two bears were transported to a forest where no other bears lived. They began to
reproduce and populate this forest area.
a. Look at the graphs below.
i. Which graph represents exponential growth of the bear population?
ii. Which graph represents logistic growth of the bear population?
iii. In the graph of logistic growth, in what year did the population reach carrying
capacity?
iv. Which graph is a more realistic representation of the growth of a bear
population?
Bear Population Over One-Hundred Years (Population #2)
2500000
270
2000000
220
Bear Population
Bear Population
Bear Population Over One-Hundred Years (Population #1)
1500000
1000000
500000
10.
Limits to population growth.
a.0Environmental Limits
1900
1920
1940
1960
Time (year)
170
120
70
20
1980
2000
1880
-30
1900
1920
1940
1960
1980
Time (year)
Brodnax
2000