Chapter 5- Changes In Populations Flashcards
What factors affect population growth?
- birth rate
- death rate
- immigration rate
- emigration rate
How do ecologists study populations?
Study
- populations’ geographic ranges
- densities and distributions
- growth rates
- age structures
What happens during exponential growth?
Larger it gets= faster it grows.
J-shaped curve
One pair gives birth to 3 pairs each give birth to 3 pairs and so on.
What is logistic growth?
Occurs when a population’s growth slows then stops, followed by a period of exponential growth.
S-shaped curve
What is carrying capacity?
The maximum number of individuals of a particular species that a particular environment can support.
What factors determine carrying capacity?
- competition
- predation
- parasitism
- disease
- natural disasters
- unusual weather
Which of the factors listed before could cause carrying capacity to change?
A catastrophic event such as a forest fire, tsunami, or volcanic eruption
Density dependent factors?
- Predation
- parasitism
- disease
- stress from overcrowding
- competition
What are density independent factors?
Factors that affect all populations in similar ways, regardless of population size and density
How has the human population size changed over time?
Drastically increased
Is human population still growing? Can it grow indefinitely?
Yes it’s still growing, no it cannot grow indefinitely
Why are population growth rates different from country to country?
- birth rates
- death rates
- age structure of a population
Are age-structure diagrams useful in predicting future population trends?
Yes, they can helps how how steady a growth rate is and predict when the population will double.
Tells whether population is stable, increasing, or decreasing
