1. Populations in Ecosystems
Different species use different reproductive strategies
Some species reach reproductive maturity very quickly and produce high volumes of offspring
These organisms tend to be small and have a short lifespan; individuals generally only reproduce once
Ex: insects, dandelions

2. Populations in Ecosystems
Some species reach reproductive maturity more slowly and produce only a few offspring
These organisms tend to be longer-lived, and individuals will reproduce more than once in a lifetime
More care is invested in each offspring, and body sizes are generally larger
Ex: whales, polar bears, humans

4. Predator and Prey Predator and prey populations affect one another
As prey increases, the number of predators slowly increases
Eventually, the increase in predators will cause the prey population to “crash”
This decrease in prey will lead to a decrease in the predator population

6. Population Growth Population sizes are not usually constant
Instead, they will increase and decrease in cycles
Limiting resource: a condition that can restrict a population’s growth
Ex: amount of water will limit populations in the desert
Carrying Capacity: the number of organisms in a population that the environment can “carry” or handle

7. Population Growth
Some species increase population size rapidly until they reach carrying capacity
Others increase slowly and never cross carrying capacity
If a population overshoots carrying capacity, the population will crash
Once the population decreases, then individuals will have more resources, and the population will begin to grow again