Ecological Challenges

Our biome work continues today with students investigating the “human caused ecological disasters” they identified yesterday for the three biomes they selected.  Student groups will present preliminary findings to the class tomorrow.  Students should create one Google Slide for each of the biomes (one disaster per biome) and the slide should include as much of the following information as possible:

  • Year(s) the human-caused ecological disaster occurred
  • Description of biome pre-disaster
  • Explanation of what humans did to cause the disaster
  • Description of biome post-disaster
  • Effect of disaster on the plants and animals (including humans!)
  • Remediation efforts (how humans have tried to “fix” the damage)

Example of slide layout:


A selection of resources are provided below:

SuperFund Sites in the USA

10 worst man-made environmental disasters

Earth’s Biomes

For our final section of the year, we end our study of Ecology first by studying the biomes of Earth, and then constructing models of the biomes complete with students solving a human-made problem found within each biome.

For our first day of work, students will assemble into groups of three students each.  Requirement: team members cannot have worked on a project together yet this year!

  • Step 1: Come up with a team name
  • Step 2: Select a unique color white board marker
  • Step 3: Given the definition of biome (a large naturally occurring community of flora and fauna occupying a major habitat, e.g., forest or tundra), race to list as many of Earth’s biomes as possible in two minutes
  • Step 4: Describe the key features of each biome, including
    • climate (the weather conditions prevailing in an area in general or over a long period)
    • dominant vegetation (plants)
  • Step 5: Select three biomes and research ecological disasters caused by humans.  Be prepared to share with the class.

Notes from the white board:


Gay-Lussac’s Law

For lesson 59, we learned about Gay-Lussac’s Law (P=kT), the third gas law needed to connect pressure, volume, and temperature.  Gay-Lussac’s Law helps explain the egg-in-a-bottle trick, where boiled water displaces the air inside a bottle, and as the water condenses, an egg placed over the bottle will be pulled inside because of the change in pressure inside the bottle.

For students who missed the demonstration in class today, see the video below:

The Lesson 59 worksheet and Lesson 59 PowerPoint are available for download.  By the end of class tomorrow, students should be able to explain the outcome of the experiment below using Gay-Lussac’s Law:

Conclusion Writing

Reminder: Lab reports (one Google Doc per team shared with Mr. Swart), and the Plants Notes organizer (one per person) are both due Friday (May 25).  

Having acquired a deeper understanding of plant biology, we set our sights on the final piece of the Baggie Garden lab report: the Discussion / Conclusion section.  Remember, lab reports are organized into at least four parts in the following order:

  • Introduction (minimum of one paragraph)
    • State the scientific concept the lab is about.
    • Describe what you know about germination and how the lab is investigating the process of germination.  Include a discussion about how the energy used for germination is different from the energy used for plant growth.
    • State the hypothesis in if/then/because format for the experiment and then explain:
      • why this particular hypothesis was selected
      • how the experiment will add to your understanding of germination
  • Procedure:
    • Consists of a numbered list of steps
    • Each step includes one action
    • Must be detailed enough (including materials used) that someone unfamiliar with the lab could exactly repeat the experiment
  • Results
  • Discussion / Conclusion
    • Connect experimental results with Hypothesis.  Explain how the experimental design enabled you to test your hypothesis.
    • Explain how each manipulated variable affected the responding variable(s).  Be as specific as possible when describing the changes observed.  For example, as light intensity decreased from 200 lux to 40 lux (a decrease of 160 lux), the number of seeds germinating decreased from 80% to 40% (a decrease of 40%).
    • Explain how the data support your conclusion.  Regardless of whether your hypothesis was correct or incorrect, you now have data to help you better understand how the variable you selected impacts germination.  Explain that connection as thoroughly as possible.  By now, you may have read additional information about seed germination which may help you explain your results.  Include as much supporting evidence as possible from the sources you have examined.  If your results contradict what is published, explain how your results are different.  Provide a scientific explanation for the trend you observe in your data.
    • Provide a minimum of three possible sources of experimental error.  Explain how each possible source of error might influence the results your results.
    • Provide one opportunity to improve the experiment.  If you were to repeat this experiment, what would you do differently, and why?  Scientists work carefully and methodically, with experiments building on each other.  Think of your next experiment as the next step beyond your current experiment.

Boyle’s Law

Before we began our study of Boyle’s Law, we reviewed Charles’s Law of Ideal Gases:

Continuing with our study of pressure and volume, students learned about Boyle’s Law in Lesson 58.  Class began with a Sci Guys video about Boyle’s Law:

After the video, students took down a few notes from the whiteboard (below) and then worked through the Lesson 58 Worksheet.  For reference, students are also encouraged to review the Lesson 58 PowerPoint.

Charles’s Law
Boyle’s Law
Whiteboard notes for the Lesson 58 lab


Seed Germination and Cellular Respiration

With our seed germination experiment coming to a close yesterday, students are taking a break from writing the lab report in order to add to their knowledge about plants. We began with a Crash Course video about vascular plants:

Next, each student was assigned to read pages 758-763 from the textbook Biology (Raven & Johnson, 4th Edition, 1996).  Students recorded definitions to vocabulary words and summarized sections using the Plants Notes organizer.  The organizer is due Friday, along with the Lab Report, and should help students improve Introduction sections and help support their writing of the Conclusion section later this week.

Data Analysis and Graphing

Today marks the final official day of data collection.  After collecting and recording Day 6 observations, students should complete their data table tracking how many of their seeds germinated.  Next, students should construct a data table showing how many seeds germinated as a percent of total seeds (per condition).  Finally, a graph of the percent germinated data needs to be made.  Both data tables and the graph need to be transferred to the Results section of the lab report.

The Results section should include a written explanation of what the data tables show.  Explain how each experimental condition affected seed germination, using the control bag of seeds as the comparison group.

Lab Report Checklist (how to know when you are done…for now)

  1. Introduction
  2. Procedure
  3. Results
    • Data Table #1 = # of seeds germinated
    • Data Table #2 = % of seeds germinated
    • Graph of Data Table #2
    • Explanation of what graph are (not what they mean)

Air Pressure

Lots of demonstrations today!  We will conduct as many demonstrations as time and resources permit.  Students are encouraged to watch the videos below to make additional observations and to help explain what is happening in each of the demonstrations.  Students will write observations and draw pictures of air molecules to visualize pressure using the space provided on the Lesson 57 Worksheet.  The Lesson 57 PowerPoint includes the definition of pressure.

Balloon in a bottle:

Soft drink can:

Submerged cup:

Air pressure mat:

Cup and card:

Balloon in a vacuum:


Egg in a bottle:

Extend Your Learning!

Ever wonder why is space a vacuum?  Great question!  Read the cleverly titled article Why is space a vacuum? and find out!

Data Collection and Measurements

With the first week of our experiment coming to a close, students should return Monday with the following sections of their lab reports completed:

  • Introduction – at least one paragraph, perhaps two, filled with information about germination (hook your reader!) and explaining why you selected your manipulated variable.
  • Procedure – detailed enough that a stranger could repeat exactly what you did!
  • Results with Data Table – create the data table in Google Sheets.  Keep track of the number of seeds that germinate each day.  Then use your data to calculate the percent of seeds that have germinated.  You will create a graph of the percent germinated data next week.  Additional data collected will improve your report and result in an improved lab report score.

All team members must participate equally to writing the lab report.  Pictures are a great way to show your reader both your procedure and your results.  Pictures can go in the Results section and should be clearly labeled and organized.

Gas Density

For the first lesson of Chapter 11, students worked with dry ice and watched a couple of teacher demonstrations involving dry ice.  To begin class, students quickly assembled into groups of 2-3 and transferred a small amount of dry ice into a deflated plastic bag which they sealed closed.  Students recorded the mass of the dry ice added to the bag, then measured the volume of the bag after the dry ice finished sublimating in order to calculate the density of carbon dioxide gas.

While waiting for the dry ice to sublimate, students hypothesized about what they might observe when water ice and dry ice were heated on a hot plate, and also what would happen when water and dry ice were added to liquid water or vegetable oil (pictured below).

Dry ice in vegetable oil (left) and water (right)

Students then observed the outcomes and recorded their observations on the Lesson 56 Worksheet.  Students also recorded the definitions of sublimation and evaporation, both of which are included in the Lesson 56 PowerPoint.  For homework, students were assigned problems 1-10 from Lesson 56 in the textbook.

Note: For students who missed class due to testing today, please watch the videos below as a substitute for participating in the lab.