WA.1. Systems (SYS)
4-5.SYS. Complex Systems: In prior grades students learned to think systematically about how the parts of objects, plants, and animals are connected and work together. In grades 4-5 students learn that systems contain smaller (sub-) systems, and that systems are also parts of larger systems. The same ideas about systems and their parts learned in earlier grades apply to systems and subsystems. In addition, students learn about inputs and outputs and how to predict what may happen to a system if the system's inputs are changed. The concept of a hierarchy of systems provides a conceptual bridge for students to see the connections between mechanical systems (e.g., cities) and natural systems (e.g., ecosystems).
4-5.SYSB. Students know that A system can do things that none of its subsystems can do by themselves.
4-5.SYSB.1. Students are expected to specify how a system can do things that none of its subsystems can do by themselves (e.g., a forest ecosystem can sustain itself, while the trees, soil, plant, and animal populations cannot).
WA.4. Life Science
LS1. Structures and Functions of Living Organisms
4-5.LS1. Structures and Behaviors: In prior years, students learned that all plants and animals have life cycles. In grades 4-5 students learn that plants and animals have different structures that work together to respond to various internal and external needs. Students compare various human and animal structures and reflect on how the different structures enable the organism to respond to external and internal needs. Students also learn that healthy body structures depend on good nutrition. These concepts are stepping-stones to later understanding of how structures are built up from cells.
4-5.LS1B. Students know that plants and animals have different structures and behaviors that serve different functions.
4-5.LS1B.2. Students are expected to describe the function of a given animal behavior (e.g., salmon swim upstream to spawn, owls hunt at night when prey are vulnerable).
4-5.LS2. Food Webs: In prior grades students learned that ecosystems include both plant and animal populations as well as nonliving resources, and that plants and animals depend on one another and on the nonliving resources in their ecosystem to survive. In grades 4-5 students learn how ecosystems change and how these changes affect the capacity of an ecosystem to support populations. Some changes in ecosystems are caused by the organisms themselves. The ability of any organism to survive will depend on its characteristics and behaviors. Humans also play an important role in many ecosystems and may reduce negative impacts through thoughtful use of natural resources. Concepts related to ecosystems, including food webs, make it possible for students to understand the interrelationships among various forms of life and between living things and their environment.
4-5.LS2A. Students know that an ecosystem includes all of the populations of living organisms and nonliving physical factors in a given area. Living organisms depend on one another and the nonliving physical factors in their ecosystem to help them survive.
4-5.LS2A.1. Students are expected to identify the living and nonliving parts of an ecosystem.
4-5.LS2A.3. Students are expected to describe how the plants and animals in an ecosystem depend on nonliving resources.
LS3. Biological Evolution
4-5.LS3. Heredity and Adaptation: In prior grades students learned about variations in inherited characteristics. In grades 4-5 students learn that some differences in inherited characteristics may help plants and animals survive and reproduce. Sexual reproduction results in offspring that are never identical to either of their parents and therefore contributes to a species' ability to adapt to changing conditions. Heredity is a key feature of living plants and animals that enables changes in characteristics to be passed on and for species to change over time. Fossils provide evidence of what ancient extinct plants and animals looked like.
4-5.LS3A. Students know that in any ecosystem, some populations of organisms thrive and grow, some decline, and others do not survive at all.
4-5.LS3A.1. Students are expected to list some reasons why some populations may not survive as well as others.