What is the main source of energy for the entire planet?

• crops
• magnetic fields
• sunlight
• the ocean

The first trophic level of an ecosystem consists of:

• plants
• herbivores
• carnivores
• detritivores

What type of animal would occupy level B in a pyramid of numbers?

• wolf
• frog
• rabbit
• grass

Which of the following habitats would have an inverted pyramid of numbers?

• The gulf of Mexico
• The prairie in Nebraska
• An oak tree in a backyard
• A rainforest in South America

Which of the following returns carbon to the atmosphere?

• photosynthesis by plants
• precipitation in the atmosphere
• burning of fossil fuels
• temperature increases

The following diagrams represent a pyramid of numbers for two different ecosystems. What do the models represent?

• the total biomass at each trophic level
• the total amount of energy in the ecosystem
• the amount of energy available at each trophic level
• he number of individuals present at each trophic level

The represents a pyramid of numbers for two different ecosystems. What is the primary consumer for the terrestrial ecosystem?

• snakes
• mice
• grasshoppers
• grasses

Which statement BEST describes how matter moves within and between ecosystems?

• Matter flows in a one-way direction

• Matter cycles between trophic levels

• Matter is made and destroyed as it is used

• Matter cycles through food webs and biogeochemical cycles.

What processes of the water cycle return water vapor directly to the atmosphere?

• water retention and runoff
• freezing and precipitation
• evaporation and transpiration
• condensation and evaporation

What is the mostly likely cause of algae blooms?

• nitrogen
• methane
• carbon dioxide
• low oxygen levels