Biology
th –9
Grade
CHAPTER 5 NOTES
CHARACTERISTICS OF A POPULATION
• DENSITY • GROWTH RATE • GEOGRAPHIC DISTRIBUTION
3 FACTORS THAT AFFECT POPULATION
• # OF BIRTHS • # OF DEATHS • # OF IND. THAT ENTER AND LEAVE A POPULATION
2 TYPES OF POPULATION GROWTH
EXPONENTIAL GROWTH
POPULATION GROWS EXTREMELY RAPID AND AT A CONSTANT RATE
LOGISTIC GROWTH
DOES HAVE A PERIOD OF EXP. GROWTH, BUT WILL STOP OR SLOW DOWN. GOES THROUGH A # OF PHASES. *Carrying capacity – total # of individuals a pop. can support
LIMITING FACTOR
FACTOR THAT CAUSES THE POPULATION TO DECREASE
• Factors that depend on the size of a population • Examples – Competition, predation, disease, parasitism
Density-Dependent Limiting Factors
Density-Independent Limiting Factors
• Affect all pop. regardless of pop. size. Examples – Natural disasters, Weather, and human activities
QUIZ – CH. 5 1. List 3 factors that affect population growth. 2. What are 3 characteristics of a population? 3. What type of growth goes through a period of rapid growth, and slows down or stops?
4. What is the term for the largest # of individuals a population can hold? 5. What type of growth grows at a constant rate? 6. List some density-dependent limiting factors. 7. List some density-independent limiting factors.