-Why might a pyramid of numbers sometimes be inverted? Give a real-world example.

-Can a single tree support hundreds of herbivores? How does this show up in the pyramid of numbers?

• Explain why a pyramid of biomass is always upright in most ecosystems, but sometimes inverted in aquatic systems.

• Calculate the total biomass at each trophic level using this example: grass = 5000 kg, rabbits = 500 kg, foxes = 50 kg. Does the pyramid make sense?

• How would deforestation affect the biomass pyramid of a forest ecosystem?

• Only 10% of energy is passed to the next trophic level. Why is energy transfer so inefficient?

• Sketch an energy pyramid for a pond ecosystem and label the energy loss at each level.

• How does overfishing affect the energy pyramid in marine ecosystems?

1. If humans consume more meat, how does it impact pyramids of energy and biomass?

2. Why might removing a top predator collapse an ecosystem? Explain using pyramids.

3. Which pyramid type (numbers, biomass, energy) best explains why large predators are rare? Why?