An invasive predatory fish is introduced into a lake. Species Population Change (%) Native small fish –65% Zooplankton +50% Phytoplankton –30% Which interaction most directly explains the phytoplankton decline?

Alpine species are particularly vulnerable to climate change because:

Which process converts atmospheric nitrogen (N2) into a biologically usable form?

Which best explains why energy pyramids are always upright?

Which of the following biogeochemical cycles is most relevant to production of ammonia in soils?

DDT accumulation led to declines in birds due to:

A grassland ecosystem shows the following annual biomass (g/m²): Trophic Level Biomass Producers 10,000 Primary consumers 1,200 Secondary consumers 150 Tertiary consumers 15 Approximately what percentage of energy is transferred from producers to primary consumers?

 Keystone species are important because they:

Which of the following best explains how overfishing can lead to fishery collapse?

Small, isolated populations are most vulnerable to: