SC15.7.5

Science (2015) Grade(s): 7

SC15.7.5
Examine the cycling of matter between abiotic and biotic parts of ecosystems to explain the flow of energy and the conservation of matter.

Unpacked Content

Scientific and Engineering Practices

Constructing Explanations and Designing Solutions; Asking Questions and Defining Problems; Obtaining, Evaluating, and Communicating Information

Crosscutting Concepts

Energy and Matter

Knowledge

Students know:

Organisms can be classified as producers, consumers, and/or decomposers.
Abiotic parts of an ecosystem provide matter to biotic organisms.
Biotic organisms of an ecosystem provide matter to abiotic parts.
Energy flow within an ecosystem.
The number of each type of atom is the same before and after chemical reactions, indicating that the matter ingested as food is conserved as it moves through an organism to support growth.
During cellular respiration, molecules of food undergo chemical reactions with oxygen to release stored energy.
The atoms in food are rearranged through chemical reactions to form new molecules.
All matter (atoms) used by the organism for growth comes from the products of the chemical reactions involving the matter taken in by the organism.
Food molecules taken in by the organism are broken down and can then be rearranged to become the molecules that comprise the organism (e.g., the proteins and other macromolecules in a hamburger can be broken down and used to make a variety of tissues in humans).
As food molecules are rearranged, energy is released and can be used to support other processes within the organisms.
Plants, algae, and photosynthetic microorganisms require energy and must take in carbon dioxide and water to survive.
Energy from the sun is used to combine molecules (e.g., carbon dioxide and water) into food molecules (e.g., sugar) and oxygen.
Animals take in food and oxygen to provide energy and materials for growth and survival.
Some animals eat plants algae and photosynthetic microorganisms, and some animals eat other animals, which have themselves eaten photosynthetic organisms.

Skills

Students are able to:

Articulate a statement that relates a given phenomenon to a scientific idea, including the cycling of matter and flow of energy among biotic and abiotic parts of ecosystems.
Identify and use multiple valid and reliable sources of evidence to construct an explanation.
Use reasoning to connect the evidence and support an explanation.
Obtain information about how food is broken down through chemical reactions to create new molecules that support growth and/or release energy as it moves through an organism from published, grade-level appropriate material from multiple sources.
Determine and describe whether the gathered information is relevant.
Use information to communicate how food is broken down through chemical reactions to create new molecules that support growth and/or release energy as it moves through an organism.
Articulate a statement that relates a given phenomenon to a scientific idea, including the idea that photosynthesis and cellular respiration cycle matter and energy.
Identify and use multiple valid and reliable sources of evidence to explain the roles of photosynthesis and cellular respiration in cycling matter and energy.
Use reasoning to connect the evidence and support an explanation of the roles of photosynthesis and cellular respiration in the cycling of matter and flow of energy into and out of organisms.

Understanding

Students understand that:

There is a transfer of energy and a cycling of atoms that were originally captured from the nonliving parts of the ecosystem by the producers.
The transfer of matter (atoms) and energy between living and nonliving parts of the ecosystem at every level within the system, which allows matter to cycle and energy to flow within and outside of the system.
The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.
Matter and energy are conserved through transfers within and outside of the ecosystem.
Relationship among producers, consumers, and decomposers (e.g., decomposers break down consumers and producers via chemical reactions and use the energy released from rearranging those molecules for growth and development.
Within individual organisms, food moves through a series of chemical reactions in which it is broken down and rearranged to form new molecules, to support growth, or to release energy.
Plants, algae, and photosynthetic microorganisms take in matter and use energy from the sun to produce organic molecules that they can use or store, and release oxygen into the environment through photosynthesis.
Plants use the food they have made for energy, growth, etc.
Animals depend on matter from plants for growth and survival, including the following:
- Eating photosynthetic organisms, thus acquiring the matter they contain, that they gained through photosynthesis.
- Breathing in oxygen, which was released when plants completed photosynthesis.
Animals acquire their food from photosynthetic organisms (or organisms that have eaten those organisms) and their oxygen from the products of photosynthesis, all food and most of the oxygen animals use from life processes are the results of energy from the sun driving matter flows through the process of photosynthesis.
Photosynthesis has an important role in energy and matter cycling within plants as well as from plants and other organisms.