Pumpkin Chemistry and The Haunted Library

What do you get when you cross the following: anatomy and physiology students, chemistry students, the school library, Halloween, the science club, and the Make-A Wish Foundation?

Just complete science FUN!!

Each year at our school, our students who are enrolled in either Anatomy and Physiology or Chemistry are required to carve a pumpkin with a theme that corresponds to the class that are taking.  As you would expect, some of the students go all out and bring in some really amazing creations, while others just do the bare minimum.  But, it always turns out to be a great day, and all involved have a lot of fun.

The library transformed!

All members of the science club stay after school one day and transform the library into "The Haunted Library"!!

The librarian is a great sport to allow us to do this to her library!

After the library has been decorated, all of the participating students bring in their carved pumpkins to put on display.  Next, you turn on the creepy music and turn on the ghosts that fly across the room, and you have a haunted library!

What did they do to my skeleton?

During the day, all students in our school are given the opportunity to visit our haunted library.  Each student pays $1.00 for admission.  And since the students are allowed to leave class (with teacher permission) to visit the library, you can well imagine that every kid in school is begging their teacher to take them to the library.  All of the money we raise goes to the Make-A-Wish Foundation.  I am proud that this year we were able to donate over $1000 to this wonderful organization!

Here are some of the pumpkins that were created for this year's haunted library.  I saved my favorites for the very last!

I will start with the one that my own daughter created!  Have you seen the movie, "Up"?  She carved the house from the movie into the bottom pumpkin, and add three helium balloon pumpkins on top.  On the left, is the pumpkin with the info from the periodic table about helium.

This one was created by an anatomy student.  Each bone in the hand and arm was clearly and correctly labeled.  Very cute!

This student did a great job carving a brain!

It's water with a bat-smile!

With my flash....

In the dark....

A model of an atom....

Carbon Dioxide....

We had two 

Einsteins!

 

A few of our special effects....

I loved this "ScArDy" Cat!

Very clever!

This student carved a pretty good heart!

And now for my very favorite!  This student did an amazing job carving a human fetus, and then placed it inside Mom's tummy!

I hope you have enjoyed this post.  It takes an incredible amount of work to pull this off, but the students loved it, and we raised so much money for a very worthy cause!  Win/win for all involved!

Happy Teaching!!

Discovery Education

I have spent the first part of this morning looking at the Discovery Education web site.  If you have never seen this site, and you teach school, you should head there right now!  It has free lessons and teaching materials for all subject areas and all grade levels.  Of course, I spent my time perusing the science section for grades 6 - 8 and 9 - 12.

Each lesson includes the following:  Objectives, Materials, Procedures, Discussion Questions, Evaluation, Extensions, Suggested Readings, Links, Vocabulary, and Standards.  Wow!!  Everything the teacher needs!

Here are some of the lessons I really liked for middle school students:

Robots:  The lesson centers around how robots will improve life for humans, especially those that have disabilities.

Transition Metals:  Students will identify and describe transition metals, discuss alloys and their benefits, and research one common alloy, its composition, properties, and uses.






Here are some of the lessons I really liked for high school students:

Underwater Forensics:  Students will discover how a team of scientists uncover the facts about a shipwreck, describe the roles of scientists and technicians on an underwater forensics team,  research a shipwreck, and demonstrate understanding of why such incidents occur.

Galileo's Dialogue:  Students will understand the following:

•	Galileo's conclusions about the position of Earth in the solar system raised objections from the Church.
•	Galileo lived at the beginning of a period in which scientific inquiry flourished.

As you can see, there are some really great activities on this site.  I hope you will find some useful lessons for your particular teaching situation.  Happy Teaching!!

Lab: Gas Exchange in Respiration

Gas Exchange in Respiration:

Qualitative Observation of Carbon Dioxide Release

It is the time of year for teaching photosynthesis and respiration to my biology students.  I think that all biology teachers will agree that these are difficult concepts to teach to our students.  Other than genetics, I think that the topics of photosynthesis and respiration may be my favorite topics to teach.  I enjoy the chemistry aspects, and I especially enjoy sitting back and marveling at how beautiful these two processes are.  I really get excited in my classroom and can often be heard saying, "Isn't it cool how this works?!"

Which do you teach first?  Personally, I like to teach respiration first.  After 28 years of teaching, I find that this approach works best for me.  I have tried it both ways, and now I always start with respiration.

It is so important to make sure that the students first have a firm grasp on the "big picture".  Emphasize the reactants and the products.  Make sure the students understand what the end result will be.  Then start adding in the details of the chemical reactions.  Once the student has a basic understanding of the relationship between these two processes, you can begin to add the details just like hanging ornaments on a Christmas tree.  As I move into the more complicated aspects of these chemical reactions, my students become more and more excited.  They quickly realize that they can really "see" the chemistry that is taking place.  

Unfortunately, I have found it very difficult to find good labs to reinforce the concepts of respiration.  I find photosynthesis labs to be more more effective.  At any rate, today I did this lab with my students:  Gas Exchange in Respiration.  The basic idea is to show students that living organisms give off carbon dioxide.  In the test tubes shown in the picture above, a small amount of phenol red has been added to each tube.  Glass beads are added to provide a barrier between the phenol red and the specimens that will be added to each tube.  As you look at the picture, the tube to the far left contains a piece of paper toweling that was dipped in a boiled yeast solution.  Tube 2 has paper toweling that was dipped into a fresh yeast solution.  Tube three contains 5-10 germinated seeds.  Tube four contains 5-10 dry seeds.  And tube 5 contains only the phenol red and no additional materials.  If the organism gives off carbon dioxide it will cause the phenol red to change from red to orange or yellow.  The tubes containing boiled yeasts and dry seeds will not show any change in the phenol red.  Fresh yeast and germinated seeds are actively respiring and will quickly cause a color change in the phenol red.

If you have great lab ideas for respiration, I would love to hear them!  Happy Teaching!

Gas Exchange in Respiration:

Qualitative Observation of Carbon Dioxide Release

Pinterest - The Latest Craze!

Are you a Pinterest addict yet?

If you have not taken a look at this site yet, then don't delay!  Head that way right now.  Pinterest is the latest craze and people are pinning like mad.  What are they pinning?  Just everything under the sun, from recipes, to clothes, to science products (!), to favorite books and movies.  Pinterest is like a huge bulletin board.  If you have something you like, you can pin it to a board that you have created.

I hope that you will check out all of my boards.  So far, I have created 34 boards.  Most of my boards are related to teaching science and you will find some great teaching materials there.  I have also found some terrific recipes on Pinterest and have pinned them to my "recipe" board.  The chocolate souffle recipe I found is to die for!

Check out my pin boards here:  Science Stuff on Pinterest!  I would love for you to become one of my Pinterest followers.

Happy pinning!

Student Designed Experiment Lab for Teaching Experimental Design in Middle and High School

Student Designed Experiment Lab for Teaching Experimental Design

Many upper middle school and high school students can list the steps of the scientific method. Far fewer can design a controlled experiment independently in a secondary science classroom.

After years of teaching high school biology, I realized that although my students could recite the steps, they struggled to apply them. Like many science teachers, I had relied on cookbook labs where students followed directions and reached an expected conclusion. But that approach does not truly build experimental design skills.

If we want students to understand experimental design, we must give them structured opportunities to design and carry out their own controlled investigations.

This student designed experiment lab has worked extremely well for me when teaching experimental design in secondary science. This investigation is designed specifically for middle school and high school science courses and is not intended as a take home science fair project.

This lab is designed for middle school and high school science classes (grades 8–12) and helps students apply the scientific method by designing and carrying out their own controlled experiment.

Teaching Experimental Design with Student Designed Experiments

Teaching experimental design in middle school and high school science requires more than having students memorize the steps of the scientific method. Students need opportunities to identify variables, define control groups, keep constants consistent, collect data, and draw evidence based conclusions from their own investigation.

This student designed experiment lab gives students structured practice with all of those skills in a classroom setting. Instead of completing a simple science fair project or following a cookbook lab, students learn how to design a controlled experiment from start to finish.

If you would like ready to use handouts for this lab, you can find them here:
Scientific Method Lab: The Student Designed Experiment

Why Student Designed Experiments Matter in Secondary Science

When students design a controlled experiment themselves, they move beyond memorization and begin applying the scientific method in a meaningful way.

They must:

• Identify independent and dependent variables
• Define control and experimental groups
• Recognize constants
• Design a data table
• Graph results
• Analyze experimental data
• Draw evidence-based conclusions

These are foundational scientific thinking skills that students need in middle school, high school, and beyond.

Teaching experimental design does take time. It requires modeling, feedback, and revision. But the depth of understanding students gain is well worth the effort.

If you are looking for additional strategies for teaching experimental design, you may also find my post on how to teach students to design experiments helpful, where I share practical scaffolding techniques and classroom examples.

How This Student Designed Experiment Lab Works

When I first introduce student designed experiments, I keep the topic simple and the materials limited. This prevents students from getting overwhelmed by content and allows them to focus on learning how to design a controlled experiment.

In this lab, students design an experiment to test how different quantities of water affect radish seed germination.

The topic is intentionally straightforward so students can focus on experimental design rather than complex biology content.

All students work on the same investigation using the same simple materials. This keeps the class moving in the same direction and allows me to provide targeted guidance. Especially in larger classes, this structure makes inquiry based learning manageable.

If your students need additional support identifying variables and control groups, you may also find my Scientific Method PowerPoint lesson helpful.

Materials for the Controlled Experiment

This lab requires only simple materials:

• Petri dishes or similar containers
• Radish seeds
• Graduated cylinder
• Water

Because the materials are basic and inexpensive, this experimental design lab is realistic for most secondary science classrooms.

What Students Must Include in Their Experimental Design

Before beginning the lab, students must submit their experimental design for approval. This step is essential. It allows for feedback and refinement before they begin collecting data.

Each student must clearly define:

• A testable hypothesis
• The independent variable
• The dependent variable
• The control group
• The experimental groups
• The constants
• A detailed procedure
• A properly structured data table

After collecting data over several days, students must:

• Graph their results
• Analyze patterns in the data
• Form a conclusion supported by evidence

This structured process helps students understand how to design a controlled experiment from start to finish.

Managing a Student Designed Experiment in a 50 Minute Class Period

This lab cannot be completed in a single class period. I require students to:

1. Submit their design for approval
2. Revise based on feedback
3. Carry out the investigation
4. Return at intervals to count germinated seeds
5. Analyze and graph data
6. Submit a final lab report

Yes, it is time consuming. But when students complete this process, they truly understand how the scientific method works in practice.

The goal is not speed. The goal is deep understanding.

Extending the Investigation

If time allows, students can design a second experiment testing a different variable, such as:

• The effect of temperature on seed germination
• The effect of pH on seed germination

By this point, students are much more confident in designing controlled experiments independently.

Ready to Teach Experimental Design with Confidence?

If you are looking for structured handouts that guide students through designing a controlled experiment, this resource includes two sets of lab materials:

• A complete seed germination student designed experiment
• A reusable experimental design packet that can be used all year

You can find it here:
Scientific Method Lab: The Student Designed Experiment

Teaching experimental design in middle school and high school science requires patience, structure, and feedback. But when students design and carry out their own controlled experiment, the scientific method becomes real.

And that makes it worth every minute.

New FREE Item: Chart of Amino Acids and Codons

If you are a biology or life science teacher, I believe that you will be able to use this!

As you know, there are 20 amino acids that are used to build all the various proteins in living systems.  When teaching about protein synthesis, I like to have my students work out this process.  I give them the DNA sequence of a particular gene, and ask them to determine the mRNA sequence, the tRNA sequence, and the amino acid sequence of the protein.  In order to determine the amino acid sequence, the students need a chart in order to look up the mRNA codons.

I have used this chart for some time and I like it best of all the ones I have used.

Here is a link to this FREE product:  Chart of Codons and Amino Acids.  I hope that you find this "freebie" useful.

Also related:  Determining the Traits of a Mystery Organism Organism Through Protein Synthesis.

Science Skills: Comparing and Contrasting in Science

Science Process Skills: Teaching Students to Compare and Contrast

Comparing and contrasting in science is an essential science process skill that helps students analyze observations and understand relationships between organisms, data, and structures. Scientists use compare and contrast skills to identify patterns, classify organisms, and draw meaningful conclusions.

In science, to compare means to identify similarities between two or more objects or organisms, while to contrast means to identify their differences. Learning how to compare and contrast in science helps students organize information, evaluate evidence, and think more critically about what they observe.

Students who develop strong compare and contrast skills become better scientific thinkers. They learn how to recognize patterns, ask deeper questions, and support their conclusions using evidence.

What Does It Mean to Compare and Contrast in Science?

When scientists compare two things, they look for the ways those things are similar. When they contrast two things, they look for the ways they are different.

Scientists use comparison in many situations, including:

• comparing two organisms to understand evolutionary relationships
• comparing the data from repeated experiments to check for consistency
• comparing experimental results to identify patterns or trends
• comparing structures in organisms to determine how they function
• comparing characteristics to classify organisms into groups

For example, when scientists compare a shark and a dolphin, they may initially notice that both animals have streamlined bodies and live in the ocean. However, careful comparison reveals important differences that help scientists classify these organisms correctly.

The shark is a fish that breathes through gills, while the dolphin is a mammal that breathes air through lungs. This important difference shows that these two organisms are only distantly related. Even though they are not closely related, both the shark and the dolphin have evolved streamlined bodies that allow them to move efficiently through water. Observing similarities and differences like these helps scientists understand how organisms are related and how they have adapted to their environments.

Teaching students to analyze similarities and differences helps them develop critical thinking and observation skills that are essential throughout biology and other science classes.

Teaching the Science Process Skill of Comparing and Contrasting

Many students struggle with comparing and contrasting because they focus only on obvious differences. Effective science instruction helps students develop the ability to observe carefully and identify meaningful similarities and differences.

One way to teach this skill is to present students with images or examples of organisms and ask them to analyze how the organisms are alike and how they are different.

Students can then use their observations to answer deeper questions such as:

• Why are these similarities important?
• Why do these differences exist?
• What conclusions can be drawn from these observations?

This type of activity helps students begin thinking like scientists.

Science Process Skills Activity: Compare and Contrast

To help students practice this important science skill, I created a lesson designed specifically to teach students how to compare and contrast scientific observations.

This activity includes an instructional presentation and student practice worksheets that guide students through the process of analyzing similarities and differences.

Instructional PowerPoint and Google Slides

The lesson begins with a short PowerPoint or Google Slides presentation that introduces the skill of comparing and contrasting.

During the presentation, students examine images of organisms and practice identifying their similarities and differences. These examples help students understand how scientists analyze observations and draw conclusions.

The slides guide students through questions that encourage deeper thinking about the importance of the similarities and differences they observe.

Printable and Editable Student Worksheets

After the instructional slides, students complete a five page worksheet that provides repeated practice with comparing and contrasting.

The worksheet includes a variety of question types that require students to:

• analyze similarities and differences
• examine biological structures
• evaluate observations
• draw conclusions based on evidence

These activities help students develop stronger observation and reasoning skills, which are essential components of scientific thinking.

Digital Versions for Google Slides and Google Forms

Both printable and digital versions of this activity are included.

Teachers can choose to use the worksheets in traditional printed format or assign the digital versions through platforms such as:

• Google Classroom
• Google Slides
• Google Forms
• Microsoft OneDrive

This flexibility makes the activity easy to use in traditional classrooms, 1:1 classrooms, or distance learning environments.

When Can This Lesson Be Used?

This lesson works well at several different points during the school year.

Many teachers use this activity at the beginning of the year to help students begin thinking like scientists and developing important science skills.

The activity also works well when teaching units on:

• classification and taxonomy
• evolution
• scientific observation
• science process skills

Because the activity focuses on observation and reasoning, it can be used in many different science contexts.

Science Process Skills Resource

If you are interested in using this activity with your students, you can view the complete resource here:

Science Process Skills: Compare and Contrast Activity

This resource includes:

• PowerPoint and Google Slides presentation
• five page printable student worksheet
• digital Google Slides student worksheet
• editable Google Forms version
• teacher guide and answer key

More Science Skills Activities

If you are looking for additional activities to help students develop important science skills, you may also be interested in these related resources.

• Student Designed Experiment post
• Scientific Method post
• Graphing Practice post
• Essential Science Skills post
• Five Essential Science Skills post

👉 “If you want a full overview of teaching science skills, read this post on essential science skills.

The Best Osmosis and Diffusion Lab for High School Biology

The Best Osmosis and Diffusion Lab for High School Biology: Engaging, Visual, and Data-Driven

Looking for the perfect biology lab to teach osmosis and diffusion?
This hands-on lab activity combines visual learning with measurable results. And, best of all, it’s easy to set up, uses common lab materials, and reinforces essential biology concepts like plasmolysis, hypotonic vs. hypertonic solutions, active vs. passive transport, and water movement across cell membranes. The first part of the experiment involves observing plasmolysis in cells. The second part of the lab is a potato osmosis lab. It is a classic hands-on experiment that helps students investigate diffusion and osmosis by measuring mass changes in potato cores placed in solutions of varying solute concentrations.

✅ Minimal prep

✅ Simple materials

✅ Microscopy, graphing, and calculations all in one lab!

If you are looking for a diffusion and osmosis lab using dialysis tubing instead of potatoes, you may also enjoy this classroom activity.

Why Every Biology Teacher Needs This Osmosis and Diffusion Lab

When it comes to teaching cell transport processes like osmosis, diffusion, and plasmolysis, it’s critical to move beyond definitions and diagrams. Students need to see it. They need to measure it. They need to analyze it.

That’s why this osmosis and diffusion lab activity has become a staple in my high school biology classroom. It checks every box:

• Reinforces microscope skills
• Visualizes plasmolysis in plant cells
• Engages students in weighing, measuring, and calculating
• Requires a hand-drawn graph
• Promotes data analysis and critical thinking
• Illustrates real-world application of scientific method

A Timeless Biology Lab That Just Works

Osmosis and diffusion are cornerstones of any cell structure and function unit. While there are many labs available on this topic, this one stands out. I’ve used countless variations over the years, and this two-part lab consistently generates the strongest student engagement and understanding.

When students literally say, “Whoa, that’s so cool!” as they watch plasmolysis unfold under the microscope, that’s a teaching win.

Part A: Observing Plasmolysis in Real Time (Qualitative)

In the first part of the lab, students observe osmosis in plant cells using a microscope. Start with a thin layer of red onion skin or a leaf from an Elodea (Anacharis) plant. Students first examine the cells in distilled water, sketch the cells, and note the position of the cytoplasm and vacuole.

Next comes the wow moment: swap the distilled water for a 15% salt solution. The plasmolysis is immediate and dramatic. Students watch as the cell membrane pulls away from the cell wall due to water loss. It’s the perfect visual demonstration of hypertonic solutions in action.

Part B: Measuring Osmosis in Potato Cores (Quantitative)

The second half of the lab brings in data analysis and graphing practice, making it ideal for reinforcing both science content and scientific skills.

Here’s how it works:

1. Use a cork borer to create uniform potato cores. If you are in a rush, just cut up the potatoes into small cubes. It still works great!

2. Mass the cores in groups of four and record the initial weight.

3. Place each group in a different sucrose solution of known molarity.

4. Let them sit overnight.

5. Re-mass the cores the next day and calculate the percent change in mass.

6. Plot the data to determine the solute concentration of the potato tissue.

7. Analyze whether each solution was hypotonic, hypertonic, or isotonic.

How Long Should Potatoes Sit in Solution During this Osmosis Lab?

In order to get the best results, cover the small beakers with aluminum foil and allow them to sit overnight. Since this lab takes a little time to set up, it is unlikely that measurable results can be obtained by the end of the class period.

Potato Osmosis Lab FAQs

What is the best potato variety for an osmosis experiment?

Russet potatoes are commonly used for osmosis experiments because they are large, firm, and easy to core consistently. Their high starch content and uniform texture make changes in mass easier to measure. That said, other potato varieties can work as long as all samples come from the same potato or variety to keep results consistent.

How long should potato cores incubate in solution during an osmosis lab?

Longer incubation times will produce more noticeable mass changes. The best measurable results will occur if the potatoes are allowed to soak overnight in their various solutions. The key is keeping incubation time consistent for all samples so results can be accurately compared.

What is a cork borer and why is it used in a potato osmosis lab?

A cork borer is a cylindrical tool used to cut uniform cores from materials like potatoes. Using a cork borer helps ensure that all potato samples have the same diameter, which improves the reliability of mass and length measurements. If a cork borer is not available, careful cutting with a knife can work, but results may be more variable.

Is this considered an osmosis lab or a diffusion lab?

This experiment primarily demonstrates osmosis, which is the movement of water across a semipermeable membrane. While diffusion is a related concept, the mass changes observed in potato cores are due to water moving into or out of potato cells in response to solute concentration. For this reason, it is best described as a potato osmosis lab that supports understanding of both diffusion and osmosis.

The beauty of this activity? It reinforces the concepts of osmotic pressure, solute concentration, and equilibrium, all while helping students master graphing and data interpretation.

Looking for a ready-to-use resource that includes student instructions, answer keys, and editable versions? Check out my Osmosis and Diffusion Lab on Teachers Pay Teachers! It's classroom-tested, student-approved, and designed to make your job easier.