Ecology Review Test

Coyotes are opportunistic predators that are found throughout most of North America. They typically feed on small mammals, insects, and fruits and vegetables. They are known for their dietary adaptability. What would be the best description of their role in the food web?

• An herbivore

• A carnivore

• An omnivore

• A decomposer

A pond ecosystem is shown in the diagram below. Which statement describes an interaction that helps maintain the dynamic equilibrium of this ecosystem?
Which statement describes an interaction that helps maintain the dynamic equilibrium of this ecosystem?

• The frogs make energy available to this ecosystem through the process of photosynthesis.
• The algae directly provide food for both the rotifers and the catfish.
• The green-backed heron provides energy for the mosquito larvae.
• The catfish population helps control the populations of water boatman and waterfleas.

A team of ecologists observed feeding patterns of several populations in the desert. The energy pyramid shown below depicts the feeding patterns the ecologist observed. Which of the following best explains the difference in the amount of available energy in the trophic levels of the desert ecosystem?

• There is less energy available in the producers because their tissues are less dense than those at higher trophic levels.
• There is more energy available in the second trophic level because less energy is needed for hunting compared to the higher trophic levels. 
• There is more available energy in the birds of prey because they have greater muscle mass for storing energy than organisms in lower trophic levels have. 
• There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels.

A diagram of a food web is shown below.Which organism receives the least amount of energy from the producers?

• Hawk
• Rabbit
• Grasshopper
• Mouse

The diagram shows the cycling of nutrients in an ecosystem. The removal of which of the following groups would cause an immediate decrease in the amount of energy flowing through the system? 

• Producers
• Consumers
• Decomposers
• Inorganic nutrients

Which of the following energy pyramids shows the correct placement of trophic levels?

• 
• 
• 
• 

If several species of carnivores are removed from an ecosystem, the most likely effect on the ecosystem will be:

• An increase in the kinds of autotrophs

• A decrease in the number of abiotic factors

• A decrease in stability among populations

• An increase in the rate of succession

Why is a mushroom considered a heterotroph?

• It creates different types of food.

• It makes food through photosynthesis

• It makes food through chemosynthesis.

• It obtains nutrients from its environment.

Mullet are local estuarine fish that move in schools and feed on plankton and plant matter. Natural predators of the mullet include spotted sea trout, sharks, pelicans and dolphins. The graph shows how the number of mullet in an area has changed over time. 

Based on the data, one student concludes that a new predator was introduced into the area during this time period. Which of the following is a likely alternate explanation for the change in the mullet population?

• mullet prey increased in the area

• mullet parasites decreased in the area

• the temperature of the area increased

• the amount of aquatic plants in the area decreased

How does the predator-prey relationship affect a population?

• The predators and prey are in competition with each other.

• Usually either the predator or the prey will become extinct.

• The predator species usually has exponential growth.

• The relationship controls the population size of both species.