Which 2 trophic levels does the bird (not the owl) belong to?
Primary consumers and secondary consumers
How is the beginning of primary succession different from the beginning of secondary succession?
Primary succession starts with bare rock (no soil).
The relationship between two organisms in which both benefit.
Mutualism
What percent of energy is transferred to the next trophic level?
10%
List the following in order from smallest to largest:
community, organism, ecosystem, population
Organism, population, community, ecosystem
List all of the secondary consumers in this food web.

Lion, jackal, wild cat, owl, snake
The two organisms that create soil in primary succession.
Lichens and mosses
The ecological relationship between ticks and humans.
Parasitism
90% of all energy in an ecosystem is lost as—
Heat
True or false: All bacteria are harmful.
False; Some bacteria are beneficial (like in the gut).
If producers receive 1000J of energy, how much energy does the trophic level containing the octopus receive?
10 J
Which succession sequence would most probably lead to the establishment of forests on barren rock areas?
lichens → mosses → grass → woody shrubs
Which relationship is mutualistic?
B. an ant that lives on a plant and defends the plant from other insects
The loss of which organism would lead to the most instability in the ecosystem?
Mouse
When a toxin is introduced into an ecosystem, it builds up in which trophic levels? Upper or lower?
The upper levels like tertiary or quaternary consumers.
Besides producers, name an organisms that is part of the trophic level that receives more energy than starfish.

Limpets, zooplankton, or mussels (primary consumers)
Nitrogen, a nutrient found in fertilizer, helps plants increase in size. Rainwater runoff often carries fertilizer into ponds and lakes.
What effect does excess nitrogen have on organisms in a pond or lake ecosystem?
Algae grows rapidly.
What is the name of the relationship between two organisms in which one benefits and the other is unaffected?
Commensalism
Which trophic level contains 1% of the energy absorbed by the producers?
secondary consumers (omnivores)
The longer they have been established, ecosystems have MORE or LESS biodiversity?
MORE biodiversity
If the jackal's trophic level has 100 J of energy, how muck energy do the producers have?

10,000 J
Black terns are a species of bird living in marshes, ponds, and marshy lakes. They feed on insects, fish, and crustaceans. They usually make their nests on loose, floating vegetation.
Which of the following environmental changes would most likely decrease the size of the black tern population?
C. A new plant species invades the environment and creates a dense cover of vegetation.
How would clams, oysters, and mussels most likely be affected if the amount of plankton in a large body of water was significantly reduced?
D. They would compete for a limited food source.
How does the movement of energy in an ecosystem differ from the movement of matter in an ecosystem?
Matter CYCLES due to decomposers but energy FLOWS and is not reused.
Which of the following human activities reduces biodiversity?
planting only red pine trees to replace native hardwood forests cut for lumber