Ch 35.2 Student notes CD

Chapter 35: Population and Community Ecology
Section Goal: The student will describe the patterns of exponential growth, relate limiting factors and carrying
capacity, compare and contrast density-dependent and density-independent factors and then identify hypotheses
for the causes of population growth cycles.
1. Exponential growth2. Limiting factor3. Carrying capacity4. Density-dependent factor5. Density-independent factorConcept 35.2 –There are limits to population growth
I. Exponential Growth of Populations
A. A population’s ability to grow partly depends on the rate at which its organisms can reproduce
B. Exponential Growth is when the population multiplies at a constant factor at constant time
intervals i.e. bacteria doubling every 20 minutes
II. Carrying Capacity
A. A population may start to grow exponentially, but eventually one or more environmental factors
will limit its growth
B. A limiting factor is a condition that can restrict a population’s growth
C. The carrying capacity is the number of organisms in a population that the environment can
maintain or “carry”
III. Factors Affecting Population Growth
A. Density Dependent Factors is a factor that limits a population more as a population density
Density-Independent Factors are factors that limit population but are unrelated to population
IV. Population Growth Cycles
A. A “boom” and “bust” growth cycle is one that increases rapidly followed by a sharp decline
B. Other growth cycles are influenced by those of other populations in their environments
Lesson Reflection:
Complete online activity 35.2 at .
Lesson Assessment:
1. Describe how a population grows with unlimited food, space, and water.
2. Describe what happens when a population reaches its carrying capacity in a particular environment.
3. Compare density-dependent and density-independent factors, and give an example of each.
4. What is a boom-and-bust population growth cycle? What might cause such a cycle?
Summary of Key concepts:
Complete the Summary of Key Concepts for 35.2 and turn into the box.
Technology/Application/Connection to real-world:
Complete the handout The Lesson of the Kaibab. Read the background, and then complete the
date graph and analysis.