How are climax communities different from pioneer communities? a. pioneer communities have complex food webs, while climax communities have simple food chains. b. pioneer communities contain few species, while climax communities have many species. c. pioneer communities have trees, while, while climax communities may only have lichens on bare rock. d. pioneer communities do not change, while climax communities will inevitably change.

Drag each tile to the correct box. the body monitors the levels of oxygen in the blood to regulate breathing. isabel is running in a marathon and is near the finish line. she feels out of breath. how will her nervous system work to generate a reaction? arrange the tiles in chronological order. isabel's breathing rate increases. sensory receptors in the arteries detect low oxygen levels. the brain sends signals through motor neurons. sensory neurons generate an impulse. the central nervous system relays an impulse to certain brain regions.