Science ObjectDigital resources are stored online in your NSTA Library.
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Interdependence of Life SciPack. It explores population balance in biomes.
Interdependent and fluctuating interactions among living organisms and populations and the abiotic components of their environment cause cyclical changes in the overall ecosystem resource equilibrium.
Interactions among living organisms within a population and among organisms of different populations take place on an ever-changing environmental stage. The nonliving environment—including land and water, solar radiation, rainfall, mineral concentrations, temperature and topography—shapes Earth’s ecosystems. Because each species can tolerate a limited range of physical conditions, the diversity of physical conditions creates a wide variety of ecosystems. In all these environments organisms use vital, yet limited, resources; each seeking its share in specific ways that are limited by biotic and abiotic factors.
- Explain why there are such diverse ecosystems on Earth.
- Given a description of changes in abiotic factors defining an ecosystem (i.e. temperature, precipitation, soil composition, atmospheric composition, amount of available solar energy) and the tolerance of a few species to these factors, identify graphs that accurately predict their effects on size and growth rate of these species.
- Identify and explain graphs that accurately represent examples of dynamic equilibrium.
- Explain how the population sizes of predators and their prey maintain a balance over many generations.