Lesson 0.5 – It’s Only a Drop of Water (Project Based Learning Plan)

Description: This lesson outlines the Project Based Learning (PBL) aspects of this entire module. The Lesson Plan is written to introduce the phenomenon that leads to question formation and it provides guidance on how to incorporate PBL elements throughout each subsequent lesson. It also guides students through tracking their own learning as they work towards answering the driving questions and showcasing their learning. The activities will take students through the questions, “What is in a drop of seawater that supports life on the planet Earth? How do we make ‘the Invisible Forest’ visible to others?” As students begin to ask their own questions and try to answer them, they will gain critical thinking skills and explore various environmental phenomena about the Invisible Forest. PBL is woven into the lessons, by design, to encourage students to express learning through Art.


See the NGSS listed as buttons in the left-hand menu and in the chart below. The buttons on the left are grouped to show the integrated three-dimensional nature of our lessons and modules. When applicable, if NGSS are addressed outside of bundles, they are listed separately. Connections to 21st Century Learning Skills and other published standards are also included in the chart below. In addition, for this lesson, here is a breakdown of:

What Students Learn
  • Students consider what is in a drop of seawater and how that drop is part of the Earth system. Through the PBL, students learn to design questions to gain new information. They evaluate and revise their questions based on new information that is presented. In the end, they learn what microbes are in a drop of seawater and how these cells contribute to the oxygen in the atmosphere. They specifically focus on phytoplankton as the source of that oxygen.
What Students Do
  • Design questions to guide their curiosity as they move through each lesson of the module.
  • Watch a clip from the movie, Water World.
  • Discuss what the world might be like if there were no land plants. They focus on the question: Where does our oxygen come from?
  • Complete a pre-assessment on what is in a drop of seawater.
  • Re-examine initial understanding of what is in a drop of seawater at the end of each lesson, incorporating new information gathered in that lesson.
  • At the end of the PBL/module, students reflect on what they learned in the module by building an artistic piece that focuses on the guiding question, “How do we make the invisible forest visible to others? And, why might that be important?”.


Aligned Washington State Standards (Next Generation Science Standards)
By completing this Lesson, students will work towards meeting the following Performance Expectation(s). They will also be able to use and/or develop their understanding of the listed Science and Engineering practice(s), Disciplinary Core Idea(s) and Crosscutting Concept(s).

HS-ETS1-2. Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.

HS-LS1-5. Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy.

Highlighted Science and Engineering Practice(s)

Highlighted Disciplinary Core Idea(s)

Highlighted Crosscutting Concept(s)

SEP-1: Asking Questions and Defining Problems

SEP-2: Developing and Using Models

SEP-6: Constructing Explanations and Designing Solutions

ETS1.C: Optimizing the Design Solution

LS1.C: Organization for Matter and Energy Flow in Organisms

CCC-5: Energy and Matter


Introduction (5 min)

Tell students, “We are about to explore a scenario.”  Show the intro video, The Invisible Forest PBL Intro Video (2.5 m)* or use this YouTube link or handout Water world Phenomenon Storyboard to introduce the phenomenon.  This sets the stage for the module and provides the hook using the movie “Waterworld”. After introducing the water world phenomenon, ask the students — What happens if the trees are all gone? What happens if the sea level rises so much that we don’t have land? What does the ocean give us?  Do not give them any answers at this point. (FYI – Answer: 40-50% of Global Oxygen, 10% coming from heroic “Pro” microbe.) (*An alternate video to use as the opening hook is the NOVA program called Earth from Space (from 1h 12 min to 1h 23 min)


This sets the stage and hooks students while getting them to think about big ideas. What does the ocean give us? The module leads students to ask: How can we measure global oxygen production? Which organisms in the sea produce oxygen? Through the lessons and activities the module introduces tools and models to measure and interpret the data collected from the sea, so that we can begin to understand the rate of oxygen production, which organisms are producing the oxygen and changes in the system that could affect global oxygen.


Project Based Learning: Introduction to asking questions (20-30 min)


Step 1: Ask students to demonstrate what is in a drop of seawater, using the ‘Drop of Seawater’ pre-assessment document


  • Instead of using the pre-assessment document, drops of seawater can be drawn on whiteboards or on large sheets of butcher paper. However, please note the instructions at the top of the document that are pertinent to understanding the scale/size of the drop of seawater. 
  • To assess individual student growth, have students do the pre-assessment individually OR to assess group dynamics and thinking have students in groups of 3-4 fill out the pre-assessment form (Students may include the following based on their level of current understanding: water (H20), Oxygen, carbon dioxide, salt, nutrients, microorganisms (plankton)

Step 2: Next, in groups of 3-4, (without adding more to their own) have students look at each other’s water drops noticing what is common and what is different between each model. If students did only one pre-assessment per group, have these groups compare their drop of seawater to other groups’ drops of seawater.  This could also be done as a gallery walk and comparison through class discussion.

Step 3: Purpose: Let the students know that the purpose of the unit is to learn more about what is in that drop of seawater and how it contributes to oxygen production on Earth.  At the end of the PBL they will need to be able to answer the following question: How do we make the invisible forest visible to others? And why might that be important?

  • To answer that question, students need to learn more about what is in the drop of seawater. As they go through the module with each lesson they will discover and add more about what is in the drop, leading up to the final class art project.

Step 4: Hand out the Know/Need to Know document, give them time as individuals to fill in the table based on their current knowledge.

  • In the ‘Know’ column, write down everything they think they know about the ocean, focusing on the ocean as an interconnected system of living and nonliving things and how energy is transferred within that system.  They can also focus on what they know either from what they saw in the movie clip or their Drop of Seawater pre-assessment. 
  • In the second column, come up with questions that focus on what they would Need to know at the end to complete the PBL guiding question: “How do we make the invisible forest visible to others? And, why might that be important?”
  • Give each group/table (of 3-4 students) time to discuss what they Know/Need to Know to answer the overarching question. Tell the groups they will share their question(s) with the whole group as a class discussion.

Step 5: Collect student responses on the whiteboard or electronically using the ‘Know/Need to know’ format. (Suggestion: electronic versions are easily displayed and referred back during the rest of the module.)*

  • Go around the room, write down everything the students share out making a list of what they know so far. This is a brainstorm, so write it all down.

Step 6: Repeat, this time collecting questions about what they Need to Know to understand the problem more.  Make the same running list. (Hint to teacher and student: it might be helpful to refer back to the questions you related to during the pre-assessment. Keep in mind that as you create the class list of questions, it is an evolving document that will change throughout the course of the module*.  Question examples students might come up with, but not limited to can be found below or as a separate document here.

Question Examples (also found here as a separate document)

PBL Lesson: 

What is in a drop of seawater that supports life on the planet Earth?

How do we make “The Invisible Forest” visible to others?

Why is the Invisible Forest important?

Is seawater going to be able to sustain life?

Is seawater going to be the same everywhere?

Lesson One:

From where do living systems acquire their breathable oxygen?

What is the geological history of oxygen on Earth?

How do we measure the production of oxygen on our planet?

Which organisms produce oxygen on our planet today?

Where does oxygen come from on earth?  

How much oxygen is in the atmosphere? 

Lesson Two:

How do we know which organisms perform photosynthesis?

How does photosynthesis convert light energy into chemical energy and generate oxygen?

What are the smallest photosynthetic cells?

How does chlorophyll interact with light? 

What instruments are used in the study of phytoplankton and chlorophyll on a global scale?

How do phytoplankton produce and/or use energy?

How do phytoplankton produce oxygen?

Are there different phytoplankton or are they all the same type? 

How do humans benefit from phytoplankton?

What are the organisms in the water that add oxygen to the air? 

What role do phytoplankton play in the ocean food chain/web? 

Lesson Three:

How do oceanographers measure the Invisible Forest (phytoplankton)?

What tools are available to measure oxygen?

How do we know phytoplankton are producing oxygen?

How do we know where phytoplankton are? 

Do changes in the ocean influence phytoplankton?? 

How much oxygen is coming from the ocean? How could we find out? 

What do we need to know to be able to measure how much oxygen is coming from the ocean?  

How can you measure the tiny microbes (phytoplankton) that you cannot see?  

How do we use our knowledge of oxygen production to protect the Invisible Forest? 

Is there more evidence we can obtain through calculation or measuring? 

How might we use models vs collecting actual data?

Lesson Four:

What are global distributions of different phytoplankton? 

How does data from different technologies tell different stories about phytoplankton? 

How can we use what we know about phytoplankton in one drop of seawater to understand the global ocean?

How can we monitor phytoplankton? 

Where can you find phytoplankton in the ocean? 

Are there different phytoplankton or are they all the same type? 

How do we know that phytoplankton are producing oxygen?

What do phytoplankton need to survive? 

Lesson Five:

How does the ocean change with depth? 

How does the ALOHA site change with time? 

How can we accurately and effectively represent data trends and patterns?


Step 7: Explain to students that we will be exploring many of their questions as we go through a series of lessons in the module that address how phytoplankton  produce oxygen for Earth as a system.

Step 8: Let students know that at the end of the module, they will redraw their drop of seawater to demonstrate what they learned. As an option, the process of redrawing or revising their drop of seawater can also occur at the end of each of the lessons. As a class we will be going back and completing the guiding question: “How do we make the invisible forest visible? And, why might that be important?”

*At the end of Each Lesson in the Module (5-10 min) Reflect by looking back at their Know/Need to know handout.  As a class, focus on the following:

  1. What questions are they able to answer now as a group based on the previous lesson? 
  2. Once they have identified the questions that they have been able to answer, have them fill out the ‘Drop of Seawater’ summary table document.  This provides them a chance to reflect on the previous lesson and how it connects to our driving questions and the unit on the whole. 
  3. Once they have filled out their summary table.  Have them go back to their “Know/Need to know” document. Are there any new questions that they would like to add to their list, based on what they now know?

During each lesson in the Module (5-10 min) (do this process at least once as part of the PBL):

  1. Have students look back at their drop of seawater pre-assessment
  2. Using two different colors of post-it notes have students revise their poster using their drop of water summary table.
    1. One color can represent ideas that they want to add to their drop of seawater.
    2. One color can represent ideas that they want to change/remove from their drop of seawater. 
    3. Post-it notes make it possible for them to move those ideas around

Career Connection

Based on how much time you have available, choose a career-connected activity below. In each case, recap what your students just learned in the lesson to the activity.

A homework/

outside of class

B 5-10 minutes in class C half of class period (~25 minutes) D entire class period (~50 minutes)
Give handout for students to watch Monish’s video and answer questions at home as homework. A + Brainstorm on interview questions for Monish using a whiteboard or projector. A + Have students think about the role of data in science. Students interview each other about math, coding, computers (some of the things Monish talked about), and positive experiences they had that enhanced skills in these areas. C + Have students report to the class on their interview results. Then have students write a short letter to a younger sibling or friend about how to succeed and enjoy a tech, science, or math track in school.

Example questions for Monish:

  • What are some similarities you found between the skills needed for a pharmacy career path and a computer science career path?
  • What advice do you have for someone to learn computer science if they do not have a computer science background?


Post PBL Module Reflection/Assessment (30 min): 

At the end of the module, students create a final drawing based on their initial drop of seawater and the revisions they have made over the course of the module.  See ‘Drop of Seawater’ Teacher Key_example. The components may change based on the level of the course. Reflection: After students have completed this post module ‘What is in a drop of seawater?’ have students reflect on what they learned.  This could be a class discussion, small group discussion or a written response.

Questions—Looking at your pre and post drop of seawater:

  1. List two or three things that surprised you the most about what you learned in the module.
  2. How has your understanding about the importance of oxygen changed as you moved through the module?
  3. If you could continue to explore in this module, which topic from the module sparks your interest the most?  What about that topic would you want to discover? Why?
  4. Looking back at our know/don’t know document as a class, identify one or two questions that did not get addressed and you have been curious to discover. 
  5. Look at that same document, what new questions would you add to the document?

Make the Invisible Forest visible to others Final Art Project (1 day to multi-day):

For the final art project, have the students brainstorm an artistic way to represent their learning as a class. Get students on board and thinking about “How do we make the invisible forest visible? And, why might that be important?” See a full description and student guide(s) below. This can be a single day in-class art project or expand to multi-day, depending on the design of the project. 

Final Art Project: Make the Invisible Forest Visible to others

Make the Invisible Forest more visible using your water drop. In a world with few land plants would we always have enough oxygen? We have more work to do to answer this question, which is why we have to keep asking questions….and conducting science research. With major changes occurring right now in the ocean, is Pro an important model organism to track? What if phytoplankton went away? If 10%? or 60%? of this source of oxygen disappeared…..Whether a Public Service Announcement poster or studio tours of student 3-D sculptures, creating art is a great way to educate the community about the importance of phytoplankton and the role they play in producing breathable oxygen. To get started hand out: Final Art Project Student Guide 

Beginning Art Project Ideas: Create a hanging mobile of seawater drops, that focuses on a specific topics associated with the module—such as balance and scale—and includes all the elements discovered in class. Make a Public Service Announcement poster (using software such as ‘Canva’) or video to inform the community. Examples: Public Service Announcement Project and rubric. Create individual student Drop of Seawater art or sculpture to display the class’s knowledge (clay or playdough is an easy medium to use). A single image using all the drops from the class, or a focus on different regions of the world can have visual impact. Or generate drops that are associated with one seawater source and how that drop might differ from another region. Team with an art class/club to design a representation of your class’s knowledge from the module. These ideas can lead the way to creating a piece of art used to educate the community about the importance of phytoplankton and the role they play in producing breathable oxygen.

Once your class Final Art Project is complete: Please visit the SEE website and use the submission form to display your class project in our showcase.  This provides ISB with great feedback on the module and a great way to show off your creativity. Share with the class or other classes, or do a gallery walk of projects. Use a self-assessment Final Art Project Peer Review form during the walk — it’s a great way to offer individual impressions and comments on the final project. Make the Invisible Forest visible to others!