Ecosystems and Environments Semester Review

• gulls
• barnacles
• marsh periwinkles
• blue mussels

• Elk are prey for mountain lions.
• Mice are herbivores that consume grasses and are preyed on by snakes.
• Owls prey on rabbits and frogs.
• Rabbits consume shrubs and are parasites of grasses.

• 
  The bacteria competed for nutrients and died after all the nutrients were consumed.
• 
  The bacteria did not reproduce in the system, and eventually each individual died at the end of its life cycle.
• The bacteria mutated from photosynthetic to carnivorous organisms and consumed one another until all the individuals were dead.
• The bacteria became diseased and were unable to survive in the closed system.

DDT is a pesticide that was once widely used to control agricultural pests and mosquitoes. However, this pesticide caused the eggshells of certain birds, including the brown pelican, to become fragile and thin. The adults would then accidentally crush the eggs while trying to incubate them.
What happened to brown pelican populations as a result of DDT use by humans?

• The populations increased much more slowly.
  
• The populations decreased as fewer eggs survived long enough to hatch.
  
• The populations remained stable over time.
• The populations increased as pelicans laid more eggs so that more offspring would survive.

• Building artificial reefs and limiting fishing activities
• introducing non-native species to fill unoccupied habitats and banning fishing
• building artificial reefs and increasing fishing activity
• eliminating non-native species and encouraging fishing for larger predatory fish

• sunlight
• soil
• nutrients
• consumers

• crabs, pilchards, and blennies
• euphausiids, sweeps, water fleas
• tiger sharks, dolphins, and octupuses
• sea urchins, crabs, and octopuses

Identify the organism that has the MOST energy in the pyramid:

• green sunfish
• pond snails
• blue herons
• coontails

Which example describes organisms competing for an ABIOTIC factor?

• Male elephant seals compete on a beach for mates.
• Brightly colored flowers attract pollinators.
• Cacti compete for water in the desert.
• Lions and hyenas compete for a downed zebra.

Which of these is a TERTIARY consumer?

• butterfly
• thrush
• grasshopper
• eagle