Biology Chapter 5 Flashcards
What is a population
A group of species in the same place at the same time
What is population defined by?
geographic distribution
population density
population size
What are the different geographic distributions
random, clustered, uniform
Define population density
individuals per unit of area
Population size
Total amount of individuals in the population
population model
A theoretical example of a population showing many of the main important factors
Population Growth
How quickly the population is growing
-Its determined by deaths, births, immigration, and emigration
Immigration versus emigration
Immigration is moving in, emigration is moving out
What are the different types of population growth
Logistic and exponential
Why does logistic growth flatten out?
When the population reaches is carrying capacity
carrying capacity
Total amount of organisms and ecosystem can support
How is population growth limited
INCREASE: Deaths, Emigration
DECREASE: Births, Imigration
Limiting factors
Factors that cause a population to be unable to grow, or kill off the individuals in the population
Density dependent factors
Limiting factors dependent on a population size
-predation, competition, parasitism, disease
Density Independent factors
Limiting factors that affect population no matter what
-natural disasters, weather, seasonal changes, human activity
Predator Prey relationship
Predator keeps prey under wraps-
if the prey population goes up so does the predators causing the prey to go back down.
r Strategist
Rapidly growing population with a high biotic potential. Constantly experience exponential growth, type 3 survivor ship curve, are generally affected by DIF
K Strategist
Steadily growing or stable population with a low biotic potential. Often at carrying capacity after experiencing logistic growth, type 1 survivor ship curve, affected by DDF
What size population is most affected by Density Independent Factors?
A Small population size because of the limited biodiversity
How does human population growth
In the past 500 years human population began growing incredibly quickly
How do developed countries compare to developing countries in terms of population growth
developed countries have slowed in population growth, developing countries are still growing
What caused a spike in population
Increased sanitation, medical, agriculture
Demographic transition
Starts: drop in deaths
Ends: drop in births
What causes the human demographic transition to end?
Women education
Age Structure diagram
A model showing the amount of people at each age
What age defines the future in an age structure diagram
pre-reproductive age females
-the more there are in comparison to other age the faster the population is increasing
Survivor ship curves
A model showing the amount of people at each age in a graph
-type 1, 2 and 3
