Population Growth
What is a population?
A group of individuals of the same species living in a specific area.
What does a limiting factor do in an ecosystem?
It restricts the size or growth of a population.
Define competition in an ecosystem.
When two or more species fight for the same limited resources.
Give one example of a group behavior in animals.
Herding, schooling, or flocking.
A forest fire wipes out 60% of a rabbit population. Is this a density-dependent or independent event?
Density-independent.
What type of growth produces a J-shaped curve when graphed?
Exponential growth.
If a population of rabbits grows rapidly and then levels off, what type of growth is this?
Logistic growth.
What is predation? Give an example.
One organism hunts and eats another (e.g., wolf and deer).
How does group behavior increase survival chances?
Provides protection from predators and increases hunting or foraging success.
Farmers overuse fertilizer that runs off into lakes, causing algae to grow rapidly. What happens next?
Oxygen depletion → fish die → decreased biodiversity.
What happens when a population reaches its carrying capacity?
Population growth slows or stabilizes because limiting factors restrict further growth.
Looking at a population graph, how can you tell when carrying capacity has been reached?
The graph levels off and fluctuates around a stable value.
What are the three main types of symbiosis?
Mutualism, commensalism, and parasitism.
Differentiate between inherited and learned behaviors.
Inherited = born with it; Learned = acquired through experience.
In Yellowstone, reintroducing wolves increased biodiversity. Why?
Wolves controlled deer/elk, allowing vegetation and smaller animals to recover.
Name two examples of density-dependent limiting factors and two density-independent factors.
Dependent: predation, competition, disease; Independent: natural disasters, weather and climate changes
A pond has limited oxygen and food for fish. What would likely happen if new fish were introduced?
Competition increases; population may crash if resources run out.
Explain how biodiversity helps ecosystems stay stable.
More biodiversity = more resilience; if one species is lost, others can fill the role.
Explain how competition for resources can drive natural selection.
Those with traits better suited to compete survive and pass on their genes.
Penguins huddle together during winter storms. What type of adaptation is this?
Behavioral adaptation for warmth and survival.
Explain how a sudden drought could affect both the population size and the carrying capacity of a deer population.
Drought reduces food/water → lower carrying capacity → population declines due to starvation or migration.
Describe how human activities can act as both a limiting factor and an enhancer of carrying capacity for some species.
Deforestation or pollution can limit species; farming or artificial habitats can increase carrying capacity for others.
What might happen if a keystone species (like sea otters or wolves) is removed from an ecosystem?
Ecosystem becomes unstable; prey or vegetation may overpopulate or collapse.
Describe how cooperative hunting in wolves could lead to long-term adaptation over generations.
Wolves with stronger teamwork or communication survive better; those traits become more common in the population.
Climate change causes earlier flowering in plants but migration timing in birds stays the same. What ecological problem might this cause?
Mismatch between food availability and breeding time; reduced survival and reproduction.