Do Now
• Collect materials from the front of the room• Turn in Symbiosis worksheet (if you didn’t do
it yesterday)• Take your seat• Remember: QUIZ ON Friday• Start working on Ecological Relationships
Model 1
Objective
• analyze population growth graphs and explain how limiting factors affect carrying capacity.
By the end of class, students will be able to:
Populations• A population is all of the organisms of one
species inhabiting a particular place
Population Size• Populations can increase or decrease in size
depending on different factors.
Population Size
• What can cause a population to grow in size?
Population Size
• What can cause a population to grow in size?
Births Immigration
Population Size
• What can cause a population to decrease in size?
Population Size
• What can cause a population to decrease in size?
Deaths Emigration
Population Growth Models
• Exponential vs. Logistic Growth
Exponential Growth
• J curve• Unlimited
resources
Logistic Growth
• S Curve Limiting factors
Which Occurs More in Nature?
Which Occurs More in Nature?
• Logistic Growth!
• Why?
• Why is the water overflowing in the picture below?
Capacity• The maximum amount something can hold
• How does this relate to logistic growth of populations?
Carrying Capacity• The population size an area can support
• Note: specific to the area and to the species!
What determines carrying capacity?
Limiting factors
• Density-dependent factors• Density-independent factors
Density Dependent
• Predation• Competition• Infectious
disease• Prey
availability
Density Independent
• Genetic diseases• Weather
Populations can exceed their carrying capacity … for a while
Please finish
• Questions 1-9, 11-13
Speaking of overpopulated
Exit Ticket
• Silently without notes!
• Why do populations have a carrying capacity?• (In other words why can’t populations
continue to grow forever?)