Essential Question How do populations change over time
- Slides: 17
Essential Question: How do populations change over time? AZ State Science Standards E 2. 3 Assess how the size and the rate of growth of a population are determined by birth rate, death rate, immigration, emigration, and carrying capacity of the environment
The blue question goes on the left side of your notes. Vocabulary and definitions marked in red go on the right side of your notes. Answer the summary questions at the end. Essential Question:
HOW DO POPULATIONS CHANGE OVER TIME § Succession – orderly, natural changes and species replacements that take place in the ecosystem
WHAT IS AN INVASIVE SPECIES? §Invasive Species are plants and animals that have migrated to places where they are not native.
HOW DO POPULATIONS GROW § Speed of growth depends on availability of limiting factors. Limiting factors – biotic or abiotic factors that restrict the numbers, reproduction, distribution, or existence of other organisms. n
WHAT ARE THE TWO TYPES LIMITING FACTORS? Density - dependent factors • The more organisms present, the more limiting the factor becomes • Disease, food, parasites, habitat
Density – independent factors • Affects all populations in the same way • Usually abiotic factors • Drought, floods, amount of light
POPULATION GRAPHS Y axis- the vertical line on a graph usually indicating the number of organisms. X axis- the horizontal line on a graph usually indicating time.
WHAT IS LINEAR GROWTH? -Steady population growth Number of organism Time
WHAT IS EXPONENTIAL GROWTH? - accelerating population growth Number of organism J - Curve Time
WHAT IS CARRYING CAPACITY? - is when population grows until limiting factors are used up then it becomes mostly steady Number of organism Time
HOW DO ORGANISMS INTERACT? Predator- the top consumer usually carnivores in a ecosystem Prey- herbivores or small carnivores that are energy for predators in an ecosystem
-Predation limits prey population size AND the amount of prey limits the predator population size. = number of rabbits = number of bobcats
WHAT IS COMPETITIVE EXCLUSION? § two species cannot coexist in the same ecological niche for very long without one becoming extinct or being driven out because of competition for limited resources
What are other things that limit populations? § Competition for resources such as food or habitat limits population size. § Overpopulation can lead to crowding and stress, decreasing the number of young successfully raised.
WHAT IS MIGRATION? §Emigration- The act of organisms leaving a specific area. §Immigration- The act of organisms entering a specific area.
§ 1. Give two examples of limiting factors? § 2. What are the 3 types of population growth? § 3. When animals are fighting over food, mates and shelter, this is an example of _____.