Energy Flow
What type of organism makes its own food, usually using sunlight?
Producer / Autotroph
Two animals hunt the same limited supply of mice. What relationship exists between them?
Competition
What term describes a resource or condition that restricts population growth?
Limiting Factor
In a food web, what do arrows represent?
Flow of Energy
What is the term for all individuals of one species living in the same area?
Population
What type of organism gets energy by eating other organisms?
Consumer / heterotroph
A tick feeds on a deer’s blood, harming the deer. What relationship is this?
Parasitism
A drought reduces the water available to animals in an ecosystem. Identify the limiting factor.
Water
In the chain grass → rabbit → fox, which organism is the primary consumer?
Rabbit
A disease spreads through a rabbit population. What will most likely happen to the number of rabbits?
Decrease
What role do fungi and bacteria play when they break down dead organisms and waste?
Decomposers
Barnacles benefit from attaching to whales, while the whales are unaffected. What relationship is this?
Commensalism
Oak trees produce fewer acorns one year. What is likely to happen to competition among squirrels?
Increase
A mouse eats seeds and a snake eats the mouse. What is the snake's trophic level?
Secondary Consumer
A protected coastal area provides manatees with more safe feeding and resting habitat. How might this affect their population?
Increase
A grasshopper eats grass, and a frog eats the grasshopper. What type of consumer is the frog?
A bird eats insects from a cow's body. The bird gets food, and the cow has fewer parasites. What relationship is this?
Mutualism
A rainforest becomes crowded with tall trees. Why might smaller plants struggle to survive?
Limited Sunlight
A food web contains grass, grasshoppers, frogs, and snakes. Predict what may happen to the frog and snake population if grasshoppers sharply decline.
Frogs will decline and then so will snakes.
The number of mice in a field increases significantly. Predict one possible effect on the hawk population.
Hawks will increase due to more food.
Why would an ecosystem eventually struggle to support plant growth if all decomposers disappeared?
Nutrients would not be recycled efficiently into the environment, reducing resources available to producers.
A hawk catches a mouse, while a mosquito feeds on a human. Explain the difference between these relationships.
The hawk and mouse show predation, in which the predator kills and eats prey. The mosquito and human show parasitism, in which one benefits while harming its host.
Snowshoe hares increase in number and consume large amounts of willow leaves. The willows produce defensive toxins, and hare numbers fall. What limiting factor most directly explains the decline?
Food availability, including the reduced supply of usable willow leaves.
A food web has several producers and multiple consumers. Explain why removing one producer species could affect organisms that never directly eat it.
The producer supports other organisms in interconnected feeding relationships, so changes can spread indirectly through the food web.
A predator population decreases shortly after its main prey population declines. Explain why the predator decline may occur after a delay.
Predators initially survive on remaining prey, but reduced food availability eventually lowers survival or reproduction, causing their population to decline.