UP:SC15.5.11

Students know:

The food of almost any kind of animal can be traced back to plants.
Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants.
Some organisms, such as fungi and bacteria, break down dead organisms (both plants or plants parts and animals) and therefore operate as "decomposers."
Decomposition eventually restores (recycles) some materials back to the soil.
Organisms can survive only in environments in which their particular needs are met.
A healthy ecosystem is one in which multiple species of different types are each able to meet their needs in a relatively stable web of life.
Newly introduced species can damage the balance of an ecosystem.
Matter cycles between the air and soil and among plants, animals, and microbes as these organisms live and die. Organisms obtain gases, and water, from the environment, and release waste matter (gas, liquid, or solid) back into the environment.

Students are able to:

Develop a model to describe a phenomenon that includes the movement of matter within an ecosystem, identifying the relevant components such as matter, plants, animals, decomposers, and environment.
Describe the relationships among components that are relevant for describing the phenomenon, including the relationships in the system between organisms that consume other organisms, including the following:
- Animals that consume other animals.
- Animals that consume plants.
- Organisms that consume dead plants and animals.
- The movement of matter between organisms during consumption.
Use the model to describe the following:
- The cycling of matter in the system between plants, animals, decomposers, and the environment.
- How interactions in the system of plants, animals, decomposers, and the environment allow multiple species to meet their needs.
- That newly introduced species can affect the balance of interactions in a system (e.g., a new animal that has no predators consumes much of another organism's food within the ecosystem).
- That changing an aspect (e.g., organisms or environment) of the ecosystem will affect other aspects of the ecosystem.

Students understand that:

A system can be described in terms of its components, like producers, consumers, and the environment, and their interactions, like the cycling of matter.

Developing and Using Models

Systems and System Models