Interpret Matter and Energy Cycles Practice Test

A simplified energy flow model for a grassland is shown below (numbers are energy units captured/available at each level):

Sunlight → Producers (grass: 10,000) → Primary consumers (rabbits: 1,000) → Secondary consumers (hawks: 100)

Heat loss arrows leave each trophic level box.

Which statement best matches what the arrows show about energy in this model?

Use the simplified nitrogen cycle model below (arrows show direction).

Atmosphere (N2) --(nitrogen fixation by bacteria)--> Soil (NH4+) --(nitrification by bacteria)--> Soil (NO3-) --(plant uptake)--> Plants (proteins/DNA) --(consumption)--> Animals

Dead organisms/waste --(decomposition/ammonification)--> Soil (NH4+)

Soil (NO3-) --(denitrification by bacteria)--> Atmosphere (N2)

Which pathway correctly traces nitrogen moving from the atmosphere into an animal and then returning to the atmosphere?