initiation assume that a pair of rabbits produces 6 offspring, and half the offspring are male and...
TRANSCRIPT
Initiation
Assume that a pair of rabbits produces 6 offspring, and half the offspring are male and half are female. Assume no offspring die. If each pair of rabbits breeds only once, how many offspring
would be produced each year for 5 years?
Unit 7EcologyDiscussion 7.3
Objectives
SWBAT...identify factors that affect population size.
Key Questions
What factors affect population size?
Words To Live By...
Population density
Carrying capacity
Limiting factor
Key Points
Three important factors can affect population size: the number of births, the number of deaths, and
the number of individuals that enter and leave the population.
The limiting factors of population growth can exist in two forms: density-dependent and density
independent.
Population DensityPopulation Density =
Number of Individuals ---------------------------
Unit areaSuppose there are 150 bullfrogs living
in a pond that covers an area of 3 square kilometers. What is the
population density of the bull frog population?
Population GrowthHow are these graphs alike? How are these graphs different?
Exponential Growth Vs. Logarithmic Growth
Under ideal conditions with unlimited resources, a
population will grow Exponentially.As resources become less available, the growth of
a population slows or stops. This is called Logistic growth.
Carrying capacity represents the
maximum amount of individuals an
environment can take.
Limiting Factors
What are some things that might cause a population of organisms to decrease?
A limiting factor is a factor that population growth to decrease. There are two major types of limiting factors: Density-Dependent Factors and Density-
Independent Factors.
Density Dependent vs. Density Independent
Population Size
Competition
Predation Parasitism/DiseaseClimate Change
Human Disturbances
Which limiting factors do you feel depend on the size of the population to have any
effect?
Which limiting factors do you feel do not depend on the size of the population to have
any effect?Dependent
Independent
Termination
What is the difference between exponential and logistic growth? Which type graph represents
growth under ideal conditions?