Unit 3 in APES covers the relationship between ecosystems and the change in their environment. The main questions to focus on throughout this unit is
What are the major characteristics of populations?
How do populations react to environmental conditions changing?
What are the differences in species’ reproductive patterns?
How can a population change be calculated using a formula?
⚡ Key Terms
This list of key terms will help you better understand the content and prepare you for the multiple choice section of the exam and FRQ.
3.1 Generalist and Specialist Species
3.2 K Selected and r selected species
K selected species
R selected species
3.3 Survivorship curves
3.4 Carrying Capacity
3.5 Population Growth and Resource Availability
3.6 Age Structure Diagrams
Age structure diagram
Top heavy age structure
Stationary age structure diagram
Inverted pyramid age structure diagram
Constrictive age structure diagram
Expansive pyramid age structure diagram
3.7 Total fertility rate
Total fertility rate
Crude Birth rate
Crude death rate
Infant mortality rate
Replacement level fertility
3.8 Human Population Dynamics
Immigration and Emigration
Density dependent factor
Density independent factor
Rule of 70
3.9 Demographic Transition
Pre industrial demographic transition
Transitional demographic transition
Industrial demographic transition
Post Industrial demographic transition
⚡ Quick Study - Key Terms
Age structure diagrams: An age structure diagram shows the distribution of population for a country. If a population is stable then there will be an equal distribution amongst the age groups. If a population is predicted to decline then there will be a large group of elders.
Biotic potential ➪ Refers to the maximum reproductive rate of a population in ideal conditions
how many times an organism can reproduce
r is much higher than K
exponential growth without limited
Carrying capacity ➪ The maximum population size of the species that the environment can sustain, given the food, habitat, water and other necessities available in the environment
Density-dependent Factors ➪ The size of the population will affect survival ➪ access to clean water and air, food availability ,disease, territory size
Density-independent Factors ➪ Affect population regardless of population density (size) ➪ weather, climate, storms fires, heatwaves, droughts
Survivorship curve ➪ A line that displays the relative survival rates of a cohort - a group of individuals of the same age- in a population, from birth to the maximum age reached by any one cohort member. Type 1,2,3 curves
The Rule of 70 ➪ The rule of 70 states that dividing the number of 70 by the percentage population growth rate approximates the populations doubling it