Unit 1.4 Ecosystem Interactions Review

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 more energy available in the second trophic level because less energy is needed for hunting compared to the higher 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 energy available in the producers because their tissues are less dense than those at higher trophic levels.

• There is less available energy in the fourth trophic level because of the loss of energy through metabolism and heat in each of the lower levels.

The diagram below 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?

• Inorganic Nutrients

• Consumers

• Decomposers

• Producers

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

• Rabbit

• Hawk

• Grasshopper

• Mouse

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 omnivore

• A decomposer

• A carnivore

• An herbivore

Which of the following correctly traces the energy transfer through the trophic levels in the marine food web shown below?

• Zooplankton → phytoplankton → krill → squid

• Seal → sea birds → fish → phytoplankton

• Phytoplankton → krill → fish → seal

• Fish → sea birds → seal → penguin

Energy within an ecosystem flows from the producers to the consumers. However, a very important group of heterotrophs are decomposers. What role do decomposers serve in an ecosystem?

• They consume the producers and provide energy for the higher consumers.

• They make their own food and provide energy for the rest of the system

• They change electromagnetic energy from the Sun into usable energy forms

• They break down organic matter into nutrients for other organisms.

Phytoplankton uses sunlight, carbon dioxide, and water in order to make their own food.

They are known as ______________.

• An autotroph

• A consumer

• A decomposer

• A heterotroph

A tapeworm infects pigs intestines. The tapeworm gets plenty of food and is able to reproduce safely. Unfortunately, the pig gets an infection, which could include diarrhea and dehydration. What type of relationship is being described?

• Mutualism

• Parasitism

• Competition

• Commensalism

The Boxer Crab carries Sea Anemones on its claw for protection against other marine organisms. The Sea Anemone gets to move around and get more food. Which type of relationship is being described?

• Commensalism

• Predation

• Mutualism

• Parasitism

Barnacles create home sites by attaching themselves to whales. As the barnacle is a filter feeder, it also gets access to more water and more food due to the relationship. The whale is left unaffected. Which relationship is being described?

• Mutualism

• Commensalism

• Parasitism

• Competition