Levels of Organization & Biodiversity
Which term describes all of the members of a single species that live in a particular area?
A. Community
B. Ecosystem
C. Population
D. Individual organism
C. Population
Which term names the organism that makes its own food using sunlight and provides energy to other trophic levels?
A. Consumer
B. Decomposer
C. Producer
D. Herbivore
C. Producer
Which of the following best describes a keystone species?
A. A species found only in a particular area
B. A species that is critical to the structure of an ecosystem such that its removal causes large changes
C. A species introduced from another region that causes harm
D. A species that reproduces rapidly in a new habitat
B. A species that is critical to the structure of an ecosystem such that its removal causes large changes
In an energy pyramid, which trophic level has the least available energy?
A. Tertiary consumers
B. Secondary consumers
C. Primary consumers
D. Producers
A. Tertiary consumers
An invasive species often causes declines in native biodiversity because it:
A. has many natural predators in the new habitat
B. increases resource availability for native species
C. competes for resources and lacks natural predators
D. reduces its own population size through disease
C. competes for resources and lacks natural predators
Which statement correctly describes energy transfer up a food chain?
A. Energy increases at higher trophic levels because organisms grow larger
B. Energy decreases at higher trophic levels because energy is lost as heat and metabolic processes
C. Energy stays constant at each level because matter is conserved
D. Energy is created at each level through photosynthesis by consumers
B. Energy decreases at higher trophic levels because energy is lost as heat and metabolic processes
Which interaction most directly reduces a prey population and can indirectly affect lower trophic levels?
A. Mutualism
B. Predation
C. Commensalism
D. Competition
B. Predation
In a food web, removal of a tertiary consumer often causes which immediate effect?
A. Decrease in secondary consumer populations only
B. Increase in one or more prey populations and potential cascading changes
C. Elimination of producers
D. No change because energy flow is unaffected
B. Increase in one or more prey populations and potential cascading changes
Population estimates in a region show that native small mammals declined after introduction of a non-native predator. Which hypothesis is best supported?
A. Non-native predator lacks predators and consumes a wide variety of native mammals
B. Non-native predator only eats plants and doesn’t affect mammals
C. Native mammals outcompete the non-native predator
D. Non-native predator decreased because of disease
A. Non-native predator lacks predators and consumes a wide variety of native mammals