4.03 Ecosystems: Activity and Lab Report
Please take time to read this document carefully. For full credit, all portions of this lab report must be
completed. Fill out all of the RED parts of this document. You may erase the red text and substitute it with
your own information. Take care to present your own work and not information copied from another source.
To complete this assignment, read every section of this document and complete the necessary parts.
During this lab, you will see how the populations of seals and whales influence each other. Whales are
predators. They consume seals. Seals are the prey.
I.
Purpose:
 Analyze graphs to determine the population size of two marine species.
 Explain how predation, birth, and death rates impact marine populations.
 Describe how biotic and abiotic factors influence marine populations.
II.
Hypotheses:
a. Prediction 1: If the starting population of the prey is higher than the predators, the resulting
population of the seals will be _______ (higher/lower) than the population of the whales.
b. Prediction 2: If the starting population of the predators is higher than the prey, the resulting
population of the whales will be _______ (higher/lower) than the population of the seals.
c. Prediction 3: If the prey growth rate increases, the resulting population of the seals will be
_______ (higher/lower) than the population of the whales. (Both starting populations set to
25.)
d. Prediction 4: If the death rate of the whales increases, the resulting population of the seals
will be _______ (higher/lower) than the population of the whales. (Both starting populations
set to 25.)
III.
Materials:
 The Population Dynamics Virtual Lab Activity
 Population Dynamics Lab Report
Biology I FLVS
Ms. Rechanek
IV.
Procedure and Data: (Complete All of the following 6 Steps)
Step 1:
Observe the following 3 graphs (graphs 1, 2, and 3). What is the highest population achieved by the whales
and seals in each graph? You will need to write this information into Table 1.
Biology I FLVS
Ms. Rechanek
Step 2:
Fill out the empty parts of Table 1 below using the information you took from Graphs 1, 2, and 3.
Table 1: Predation and Carrying Capacity
Trial #
Starting Seal
Population
Number
Starting Whale
Population
Number
1
25
25
2
50
25
3
25
Highest Seal
Population Number
Highest Whale
Population Number
Biology I FLVS
Ms. Rechanek
Step 3:
Observe the following 2 graphs (graphs 4 and 5). What is the highest population achieved by the whales and
seals in each graph? You will need to write this information into Table 2.
Biology I FLVS
Ms. Rechanek
Step 4:
Fill out the empty parts of Table 2 below using the information you took from Graphs 4 and 5.
Table 2: Growth Rate and Capture Efficiency
Trial #
Seal Birth Rate
Whale Birth
Rate
1
0.05
0.005
2
0.09
0.005
Highest Seal
Population Number
Highest Whale
Population Number
Step 5:
Observe the following 2 graphs (graphs 6 and 7). What is the highest population achieved by the whales and
seals in each graph? You will need to write this information into Table 3.
Biology I FLVS
Ms. Rechanek
Step 6:
Fill out the empty parts of Table 3 below using the information you took from Graphs 6 and 7.
Table 3: Death Rate and Capture Efficiency
Trial #
Whale Death
Rate
Whale Capture
Efficiency
1
0.05
0.005
2
0.09
0.005
Highest Seal
Population Number
Highest Whale
Population Number
Biology I FLVS
Ms. Rechanek
V.
Reflection Questions:
Answer the following 6 questions in complete sentences.
1.
Using Table 1, which of the three trials produced the highest population for both the whales
and the seals? Why do you think this trial had the best outcome for the whale and seal
populations? Hint: Think about the initial population size of the prey.
Write your answer here. Make sure to answer both questions.
.
2.
Using Table 2 and 3, explain how the birth rates of the seals and the death rates of the whales
affected the population for both whales and seals.
Write your answer here. Make sure to answer both parts of the question.
3.
Climate change (an abiotic factor) has slowly decreased habitat for the arctic seals. How
would this affect the carrying capacities for both the whales and the seals? Tip: Go over the
definition of carrying capacity found in the 4.03 lesson
Write your answer here. Make sure to answer both parts of the question.
4.
If another source of prey were available to the whales, what changes in population size would
you expect for the seals and the whales? Hint: Think about how this would affect their
carrying capacity.
Write your answer here.
5.
In this lesson, you learned about two patterns of population growth and decline, the sigmoid
and peak phenomena. Does the seal and killer whale relationship represent a sigmoid or peak
phenomenon? Please provide supporting details. Tip: Review the definitions of sigmoid and
peak phenomena on page 2 of the 4.03 lesson.
Write your answer here. Make sure to EXPLAIN your answer.
6.
What are the limitations of the population dynamics lab? Is the lab activity a realistic
representation of an arctic marine ecosystem? Note: Please provide detailed support for your
opinion.
Write your answer here. Make sure to answer both questions.
Biology I FLVS
Ms. Rechanek