Dude, Check Out These Diatoms!

Subject: Life Science
Grade Level: 6-8

Summary

In this activity, students will read about diatoms; an often overlooked but vitally important photosynthesizing microalgae. They will use information from the text, combined with their knowledge of photosynthesis to fill in the blanks of a worksheet about diatoms. Then, they will complete a model that shows the photosynthesis process in diatoms. Additionally, they will use their knowledge of food chains and matter flow to model the role of diatoms in the ocean ecosystem. Students will also color this activity, which folds into a display-friendly brochure that is perfect for showcasing student work.

Materials and Preparation

This resource is designed to be used after students have been introduced to the chemical reaction of photosynthesis. Teachers may choose to use this resource for a variety of purposes. Suggestions include as a graded performance task, end-of-unit project, extension opportunity or even a science fair project.

Teacher prep: print out student pages in black and white. Pages D and E should be printed separately from A, B and C so that the brochure can be printed in landscape format. The PDF of page D is “upside down” so that when printing pages D and E two-sided, the brochure is oriented the correct way.

Student materials: pencil, colored pencils, black marker, computer access optional (for viewing additional resources).


Learning Objectives

Objective #1
Describe the key molecules, cellular structures and energy transfers involved in photosynthesis.
Objective #2
Develop a model showing the photosynthesis chemical reaction at the cellular level within a diatom.
Objective #3
Develop a model to describe the flow of matter and energy within a marine food chain.
Objective #4
Explain the role of diatoms in the global matter and energy cycle.

Opening Activity

This resource is designed to be used after students have been introduced to the chemical reaction of photosynthesis.

A hook could involve showing students SEM and light microscope pictures of diatoms without context and having them guess what they are and their purpose. The teacher could then tell the students that these “things” are responsible for making 20% of the oxygen we breathe. Discussion could be guided to what students know about a chemical reaction in which oxygen is a product, etc.


Activity Overview

In this assignment, students will read about diatoms; an often overlooked but vitally important photosynthesizing microalgae that are especially abundant in the cold, nutrient-rich waters of the Southern and Arctic Oceans. They will use information from the text, combined with their knowledge of photosynthesis to fill in the blanks of a worksheet about diatoms. Then, they will complete a model that shows the photosynthesis process in diatoms. Additionally, they will use their knowledge of food chains and matter flow to model the role of diatoms in the ocean
ecosystem. Students will also color this activity, which folds into a display-friendly brochure that is perfect for showcasing student work.

Teachers may choose to use this resource for a variety of purposes. Suggestions include as a graded performance task, end-of-unit project, extension opportunity or even a science fair project. The assignment can be graded on a rubric based on the aligned standards by using a point system.

Questions to help introduce the topic:

  • Where does the oxygen in the air we breathe come from?
  • Which plants do you think produce the most oxygen?
  • How much of the Earth is covered in land? How about water?
  • Do you think there is anything in the water that photosynthesizes? How would this work?

Questions to extend thinking:

  • Why do diatoms have a huge variety of shapes? What are the different shapes useful for?
  • How are diatoms similar to and different from other plankton in the ocean?
  • Diatoms can be found throughout the ocean and even in freshwater areas, but they are particularly abundant in the polar regions (Arctic Ocean and Southern Ocean). Why do you think this is the case?

Reflection

Teachers will review student work either formatively or summatively (depending on the teacher’s needs and time constraints) and provide feedback. Students should also be able to make corrections and resubmit work in order to demonstrate proficiency in the learning objectives.


Supporting Documents


This resource was developed as part of the Polar STEAM Educator Fellowship.

Images not otherwise credited came from vecta.io and canva.com. Informational text was created by ChatGPT and modified for clarity and correction by myself.

Special thanks goes to the SNOWBIRDS II science team and all ship crew and support staff of the Nathaniel B. Palmer on the NBP2410 research cruise in the Southern Ocean. They inspired this resource!

Additional Standards Information:

  1. MS-LS1-6: Construct a scientific explanation based on evidence for the role of photosynthesis
    in the cycling of matter and flow of energy into and out of organisms.
  2. MS-LS2-3: Develop a model to describe the cycling of matter and flow of energy among living
    and nonliving parts of an ecosystem.

Standards:

Science Practice 2
Developing and using models
Science Practice 6
Constructing explanations (for science) and designing solutions (for engineering)
Crosscutting Concept 5
Energy and matter: flows, cycles and conservation
LS 2
Ecosystems: interactions, energy, and dynamics

Polar Literacy Principles:

4
Food: The Polar Regions have productive food webs.

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