Lesson 5 — Growth Patterns


Practice Problems

  1. Assume species A was introduced into a new environment. Population counts produced the following data:

    Generation

    Population (N)

    1

    2

    2

    3

    3

    4

    4

    8

    5

    15

    6

    31

    7

    32

    8

    33

    9

    33


    Graph the data from the table. Use the graph to answer the following questions.

    1. Is the population growing in a logistic pattern or exponential pattern? Support your answer. What is the shape of the curve?

    2. What is K (carrying capacity) of this population?

    3. List four density-dependent factors that could contribute to environmental resistance.

    4. Provide two density-independent factors that could affect K in this population. State whether each factor would increase or decrease K.

  2.   Use the graph below to answer the following questions.


    Human Population Curve from 10000 BC to Present. Public Domain.


    1. At approximately what year did the human population enter the exponential growth phase?

    2. Prior to that time, what was the approximate carrying capacity of Earth?

    3. State four significant developments that began to increase the carrying capacity from that time.

    4. Provide two pieces of evidence that demonstrate how density-dependent factors are contributing to environmental resistance in human populations.


    1. Logistic: shows a lag phase, exponential phase, leveling to carrying capacity, S-shaped curve

    2. K is approximately 33.

    3. Lack of food and/or water, increase in disease (parasitism), increase in predators, lack of oxygen (if aquatic), lack of space (territory, nesting sites)

    4. High snowfall (decrease K), warm winter temperatures due to global warming (increase K)

    1. Late 1800s

    2. Approximately 1/4 billion or 250 million

    3. Use of fossil fuels for industry increased productivity, modern agricultural methods increased food supply, medical advances decreased death rates, and the development of synthetic fertilizers increased food supplies.

    4. Famine, diseases that spread rapidly due to high density (HIV), lack of water
      The growth rate has slowed from an exponential rate.


Watch and Listen

To review these concepts and understand graphing, watch the following video. You may choose to make notes as you view the presentation:



 ©Alberta Education. Patterns of Population Growth and Management: Conserving Our Future. (0:00-28:53) Series 42. LearnAlberta.ca 

 


Biology 30 © 2008  Alberta Education & its Collaborative Partners ~ Updated by ADLC 2019