1. Are the third-order heterotrophs consumed by gungal decomposers?

My guess:Yes?

2. Which of the following fixes atmospheric N2 (nitrogen gas)?
A. photosynthesis
B. symbiotic bacterianon the roots of legumes
C. uv light
D. decay organisms
E. autotrophs
My guess: B?

3. Which ecological pyramid best explains why food chains are typically only three or four links long?
A. Pyramid of biomass
B. Pyramid of energy
C. Pyramid of numbers
D. None of the above
My guess: B? Because only around 10% of the energy will released to the next level?

Thank You! :-]