Unit 3: Living Systems

Disciplinary Core Ideas, Science & Engineering Practices, Crosscutting Concepts, Supporting Standards:

• 5-PS3-1

• 5-LS1-1

• 5-LS2-1

• 5-ESS2-1

• 5-ESS3-1

Concepts & Skills:

1. Systems: Students are introduced to a system as a collection of interacting parts that work together to make a whole or produce an action. They explore Earth as a system, focusing on the biosphere and describing ecosystems by looking at feeding relationships and energy transfers, described as food webs. Students model food chains and food webs in a wood ecosystem and a marine ecosystem. Each group of students sets up a red worm habitat to study detritivores and the role of decomposition in ecosystems.

Students will know:

• A system is a collection of interacting objects, ideas, and/or procedures that together define a physical entity or process.

• Earth can be described as the interaction of four earth systems: the rocky part (the geosphere), the atmosphere, the water (the hydrosphere), and the complexity of living organisms (the biosphere).

• Food webs are made up of producers (organisms that make their own food), consumers (organisms that eat other organisms to obtain food), and decomposers (organisms that consume and recycle dead organisms and organic waste).

• A kelp forest has similarities to a rain forest (vertical layering). Phytoplankton are the major producers in most aquatic systems (both marine and freshwater).

• Food webs and competition for resources exist in marine systems.

2. Nutrient Systems: Students investigate nutrient systems of yeast, plants, and animals. They design an investigation to determine the necessary conditions for activating dry yeast. They plant wheat and observe the seedlings to determine which plants have chlorophyll. Students infer that the plants growing in light are producing food to provide nutrients to their cells. Students investigate how animals acquire nutrients by eating and digesting food.

Students will know:

• Yeast is a single-celled fungus. Dormant yeast cells can become active when provided with water, warmth, and sugar as a food source. Carbon dioxide is a waste by-product of yeast metabolism.

• Chlorophyll is the green pigment that absorbs sunlight in the cells of producer organisms.

• A nutrient is a substance, such as sugar or starch, that is used by a cell to produce the energy needed to perform the functions of life.

• Plants make their own food by photosynthesis. Green plant cells make sugar (food) from carbon dioxide and water in the presence of sunlight, and release oxygen.

• Animals obtain nutrients by eating other organisms.