Learning Resource Type

Learning Activity

Let's Talk About the Nitrogen Cycle

Subject Area

Science

Grade(s)

6

Overview

This activity will utilize the talking drawings strategy, in which the teacher will introduce the nitrogen cycle using an interactive presentation to explain this biogeochemical cycle in a pictorial format. As the teacher describes the process during the presentation, the students will create their own annotated diagram to model the nitrogen cycle.

This activity results from the ALEX Resource Development Summit.

    Science (2015) Grade(s): 6

    SC15.6.7

    Use models to construct explanations of the various biogeochemical cycles of Earth (e.g., water, carbon, nitrogen) and the flow of energy that drives these processes.

    Unpacked Content

    UP:SC15.6.7

    Vocabulary

    • Biogeochemical
    • Biotic
    • Abiotic
    • Atom
    • Water cycle
    • Carbon cycle
    • Nitrogen cycle
    • Chemical compound
    • Hydrogen
    • Oxygen
    • Gravity
    • Atmosphere
    • Water vapor
    • Crystallize
    • Transpiration
    • Evaporation
    • Condensation
    • Precipitation
    • Glacier
    • Aquifer
    • Ice sheet
    • Organism
    • Decompose
    • Respiration
    • Element
    • Chemical process
    • Ecosystem
    • Geosphere
    • Carbon dioxide
    • Methane
    • Photosynthesis
    • Fossil fuel
    • Nitrogen
    • Carbon
    • Amino acid
    • Protein
    • DNA
    • Molecule
    • Bacteria
    • Fertilizer
    • Livestock
    • Nitrate

    Knowledge

    Students:
    • The cycle of atoms between living and non-living things is known as a biogeochemical cycle.
    • Biogeochemical cycles interact through biotic and abiotic processes.
    • Biotic involves living or once living things such as plants, animals, and bacteria.
    • Abiotic involves nonliving things like air, rocks, and water.
    • Biogeochemical cycles may include, but are not limited to, the water, carbon, and nitrogen cycles.
    • The water cycle is the continuous process by which water is circulated throughout the earth and the atmosphere.
    • Water is a chemical compound made up of the elements hydrogen and oxygen.
    • Global movements of water and its changes in form are propelled by sunlight and gravity.
    • Energy from the sun drives the movement of water from the Earth (e.g., oceans, landforms, plants) into the atmosphere through transpiration and evaporation.
    • Water vapor in the atmosphere can cool and condense to form rain or crystallize to form snow or ice, which returns to Earth when pulled down by gravity.
    • Water continually cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation and crystallization, and precipitation, as well as downhill flows on land.
    • Gravity causes water on land to move downhill (e.g., rivers and glaciers) and much of it eventually flows into oceans.
    • Some liquid and solid water remains on land in the form of bodies of water, glaciers and ice sheets or can be stored below ground in aquifers.
    • Some water remains in the tissues of plants and other living organisms, and this water is released when the tissues decompose. Water is also released by plants through transpiration and by other living organisms through respiration.
    • Carbon is an element found in the oceans, air, rocks, soil and all living organisms.
    • Carbon is the fundamental building block of life and an important component of many chemical processes.
    • In a process called the carbon cycle, carbon is exchanged among Earth's oceans, atmosphere, ecosystem, and geosphere.
    • Carbon is present in the atmosphere primarily attached to oxygen in a gas called carbon dioxide (CO2), but is also found in other less abundant but climatically significant gases, such as methane (CH4).
    • With the help of the Sun, through the process of photosynthesis, carbon dioxide is pulled from the air to make plant food.
    • Through food chains, the carbon that is in plants moves to the animals that eat them. When an animal eats another animal, the carbon is transferred.
    • When plants and animals die, their bodies, wood, and leaves decay bringing the carbon into the ground. Some become buried miles underground and will become fossil fuels in millions and millions of years.
    • Organisms release carbon dioxide gas through a process called respiration.
    • When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas.
    • The oceans, and other bodies of water, soak up some carbon from the atmosphere.
    • Nitrogen is an element found in living things like plants and animals.
    • Nitrogen is also an important part of non-living things like the air and the soil.
    • Nitrogen atoms move slowly between living things, dead things, the air, soil and water.
    • The continuous process by which nitrogen is exchanged between organisms and the environment is called the nitrogen cycle.
    • Most of the nitrogen on Earth is in the atmosphere as molecules of nitrogen gas (N2).
    • All plants and animals need nitrogen to make amino acids, proteins, and DNA, but the nitrogen in the atmosphere is not in a form that they can use.
    • The molecules of nitrogen in the atmosphere can become usable for living things when they are broken apart during lightning strikes or fires, by certain types of bacteria, or by bacteria associated with bean plants.
    • Most plants get the nitrogen they need to grow from the soils or water in which they live. Animals get the nitrogen they need by eating plants or other animals that contain nitrogen.
    • When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use. Other types of bacteria are able to change nitrogen dissolved in waterways into a form that allows it to return to the atmosphere.
    • Certain actions of humans can cause changes to the nitrogen cycle and the amount of nitrogen that is stored in the land, water, air, and organisms.
    • The use of nitrogen-rich fertilizers can add too much nitrogen in nearby waterways as the fertilizer washes into streams and ponds. The waste associated with livestock farming also adds large amounts of nitrogen into soil and water. The increased nitrate levels cause plants to grow rapidly until they use up the supply and die. The number of plant-eating animals will increase when the plant supply increases and then the animals are left without any food when the plants die.

    Skills

    Students are able to:
    • Use a model of the various biogeochemical cycles and identify the relevant components.
    • Describe the relationships between components of the model including the flow of energy.
    • Articulate a statement that relates a given phenomenon to a scientific idea, including the various biogeochemical cycles of Earth and the flow of energy that drives these processes.

    Understanding

    Students understand that:
    • The transfer of energy drives the motion and/or cycling of matter of the various biogeochemical cycles.

    Scientific and Engineering Practices

    Developing and Using Models

    Crosscutting Concepts

    Stability and Change

    Phase

    During/Explore/Explain
    Learning Objectives

    Learning Objectives

    Students will create and use a model to construct an explanation of the nitrogen cycle.

    Activity Details

    1. The students will need a blank sheet of paper and a pencil. Students may also use colored pencils/pens/crayons/markers to add color to their model if desired. 

    2. The teacher should present the Google Slide Presentation, "Talking Drawings Nitrogen Cycle" for the students to view.

    3. The students should begin by writing the three facts about the nitrogen cycle at the top of their paper. Then, the students should turn their paper sideways (landscape orientation) for the rest of the presentation.

    4. The teacher should use the interactive presentation to explain the steps of the nitrogen cycle. As the teacher presents the information, the students should draw the model on their paper. The teacher should be sure to encourage students to add additional notes or other important ideas to the diagram.

    Note: The teacher should be sure to thoroughly explain to students what to draw, while also explaining the scientific concepts related to the nitrogen cycle. The teacher should feel free to add to and expand upon the basic explanation of the nitrogen cycle depicted in the slide show. 

    Example script: "First, draw a line going across the middle of your paper. Color everything below this line brown and add some green grass on top. This represents the rocks of Earth's crust. Now, draw the sun and a few clouds. These items show that the nitrogen cycle is a natural process that happens within the geosphere and atmosphere. Now, write the note 'Nitrogen is in our atmosphere'. This step is where we will begin our discussion of the nitrogen cycle, although it truly has no 'beginning' or 'end'."

    5. Review the "Takeaway Points" with students to reiterate the key vocabulary words and ideas related to the nitrogen cycle. 

    Assessment Strategies

    Assessment Strategies

    On the back of the paper with students' models, have students write the role that each of these items plays in the nitrogen cycle:

    • animals
    • plants
    • bacteria
    • lightning
    • decomposers

    For example, students may write that lightning changes nitrogen gas into a form that can be used. 

    The teacher should collect students' papers to assess their model created during the activity. The final response will allow the teacher to assess students' understanding of the model. 

    Background and Preparation

    Background / Preparation

    The teacher will need internet access and the ability to project the presentation.

    Each student will need at least one sheet of paper (notebook or blank white paper). Students will need a pencil. If desired, students can add color to their diagram with colored pencils/pens/crayons/markers.

    Digital Tools / Resources

    ALSDE LOGO