Ecosystems Answer Key
Which list shows a possible order in which energy moves through an ecosystem?
- herbivore, carnivore, sun, producer, decomposer
- sun, producer, herbivore, carnivore, decomposer
- sun, producer, predator, consumer, decomposer
- producer, sun, carnivore, herbivore, decomposer
Which of the following descriptions about the organization of an ecosystem is correct?
- Communities make up species, which make up populations
- Populations make up species, which make up communities
- Species make up communities, which make up populations
- Species make up populations, which make up communities
Which is a biotic factor that affects the size of a population in a specific ecosystem?
- average temperature of the ecosystem
- type of soil in the ecosystem
- number and kinds of predators in the ecosystem
- concentration of oxygen in the ecosystem
When is an ecosystem able to best support a variety of organisms?
- when organisms share food and habitats equally
- when competition for food is controlled by humans
- when physical-space needs of organisms are met
- when organisms use the parts of the ecosystem differently
Deers and zebras feed on grasses and other plants. Leopards and lions feed on deers and zebras. Which of these is the role of deers and zebras in this ecosystem?
In an ecosystem, sometimes more than one animal is a predator to the same animal. For example, the great barn owl and the the bald eagle both share a habitat, and they both hunt mice. Which answer explains how this relationship can work?
- They are both hunted by the red fox.
- The eagle migrates to other ecosystems
- The owl hunts at night and the eagle hunts during the day
- There is an overpopulation of owls
A non-native plant is introduced into a diverse, mature ecosystem in equilibrium. If the plant has no enemies and thrives in the ecosystem, how will it affect the community?
- The number of native species will decrease.
- The native species will become more like the new plant.
- The native species will become extinct.
- The number of native species will not be affected at all.
Mountain lions give birth to their young in the spring. How does this reproductive adaptation increase the young mountain lions' survival?
- There is less competition for warmth in spring.
- Predators only eat plants during spring.
- More food is available to young during spring.
- Springtime temperatures make predators hibernate.
In 1994, an enormous amount of African farmland was devastated by a very large increase in the population of mice. Mice population in some areas rose to as many as 195 mice per square meter. Which of these factors MOST likely contributed to such a large population of mice?
- Mild climate and high crop production
- Excessive heat and low snake population
- Wet climate and no pesticides
- Warm weather and cloudy skies
In an ecosystem, birds depend on insects to survive. If someone spreads pesticide to control the insect population, which of the following is most likely to happen?
- The bird population will increase.
- The bird population will decrease.
- The bird population will decrease, then increase.
- The bird population will increase, then decrease.