Biology Lessons Part 2: Population Biology


 Lesson 2.7: How Do Populations Grow?

Knowledge Mapping Exercise


Approximately 1 hour.


Once you have completed this knowledge mapping exercise you should be able to:


Use a semantic network as the basis for writing an essay.

 Exercise 1  Preparing a Writing Exercise for Fifth or Sixth Graders Beginning with a Small Population Growth Net
 Introduction Imagine that you are teaching this lesson, "How Do Populations Grow?," to your class of fifth or sixth graders. Assume they are familiar with knowledge mapping using SemNet.
  1. First determine the goal of the exercise. Supposing the goal is to help students understand the basic factors affecting populations and population growth.

The assignment will be for the students to write a one-page essay based upon a small semantic network called "2.7d Pop Growth Exercise Net."

  3. First ask your students to construct an outline from the net, including both the relations and the concepts. You could give them the computer-based net to work from, or the graphic frames from the net captured in Figures 1 and 2 at the end of this lesson.
4 You could either construct the outline with the entire class participating, or you could ask your students to do it in small groups.
  5. Finally, ask your students to use this outline to write a one-page essay about population growth.
Figure 1. Graphic frames from "2.7d Pop Growth Exercise Net."
Figure 2. Graphic frames from "2.7d Pop Growth Exercise Net" continued.
Figure 2. Graphic frames from "2.7d Pop Growth Exercise Net" continued.


composed of non-living environment

includes water supply

includes climate

includes weather

includes solar energy

includes habitat

includes shelter

composed of living environment

includes community

includes population

has characteristic popultaion size

determined by births

increased by food supply


decreased by predation

decreased by disease

decreased by pollution

decreased by competition

determined by deaths

increased by predation

increased by disease

increased by pollution

increased by competition


decreased by food supply

determined by immigration

determined by emigration

determined by carrying capacity

has characteristic population equilibrium

has characteristic population growth pattern

includes S curve

includes J curve

includes Boom and crash cycle`

includes exponential growth

has characteristic genetic variation