It doesn't matter what age you are, glow in the dark experiments are a blast!
Did you know that tonic water glows under a black light? It has a chemical in it called "quinine" that causes it to glow. You can substitute out tonic water for regular tap water in some of your go-to experiments to make them glow! Here are a few of my favorites:
Ooblek is super fun to make when learning states of matter. Is it a solid? Is it a liquid? (It's a colloid). To make ooblek, you normally mix 1 part water to 2 parts cornstarch. Sub out tap water for tonic water and now you have a glowing non-Newtonian fluid. Around Halloween we call them "ghost guts!"
When teaching cell membranes, many teachers do the classic rubber egg experiment. In this lab, you begin by dissolving the shell of an egg with vinegar (change out the vinegar on day 2 and continue to let it sit about 2 more days). Once your shell is dissolved you are left with the membrane of the egg sans shell. You can take it a step further and soak your rubberized egg in different liquids such as corn syrup and see what happens. This simulates osmosis and how cells swell in hypotonic solutions and shrink in hypertonic solutions.
To make your rubber egg glow, use a 50-50 mixture of vinegar and tonic water. (You could even be sneaky and add tonic water to a random few beakers from the class and freak them out by telling them they must have gotten radioactive eggs).
DIY LAVA LAMP
Want to make your own lava lamp? Fill a container with 50% tonic water and 50% vegetable oil. Turn off the lights, add your black light, drop in an alka selzer tablet, and enjoy the show! This can be done to reinforce density (layers) and chemical reactions (CO2 bubbles).
Looking for more spook-tacular Halloween science ideas? Check out this blog post!
Writing out CLEAR and DESCRIPTIVE scientific procedures is hard for students. It takes practice! Many teachers start off with a fun activity like how to make a peanut butter and jelly sandwich. Students will likely forget some important steps! This Youtube version made me smile:
Anywho, it's important for students to be given opportunities to practice writing experimental procedures and not just be given what we call "cookbook labs" where everything is provided for them.
Here are some ways you can practice:
1. I created a set of 20 unique writing prompts that provide students experimental questions. I like that they not only get to practice writing procedures, but also get critical thinking practice- HOW could they test and set up an experiment to answer the question? It can be helpful to work through an example as a class and then set them loose.
(If you are interested in other writing prompt sets, check out this post).
2. I came across this cool flextangle template and immediately thought "Students will love this! But how do I connect it to my curriculum?"
I think it would be fun to put students in pairs, and chop the paper in half- give one student the foldable template and the other student the directions. Have the student with the directions explain how to cut and fold the flextangle and see if they can do it successfully. After a while, you can show them the video of how the flextangle should work and see how they did. While students won't actually be writing procedures, they will be explaining procedures, which is still great practice.
3. Have a favorite demo you love? Sneak in some writing practice! Show students the demo and tell them to watch what you do very carefully. After the demo, have them write out what you did step by step. You can do the demo a second time if they need to see it again to catch all the steps. After the demo, have a few students read their procedures out loud and see how well they did.
4. In this free activity from Amy Brown Science, students build a unique structure and write out the procedures on how they built it. Then they swap instructions with another student and see if they can replicate the structure.
What other ways do you have students practice writing procedures? Leave me a comment!
Want a new way to review the scientific method and variables at the beginning of the school year? Try having students conduct a consumer science experiment! In this lab students will chose two products that they use in their everyday life and design an experiment to test it's effectiveness.
What's great about this experiment is:
Possible experiments could include:
Prior to "setting students loose" with the task, I would remind them to only choose ONE variable, and review what a controlled experiment is. For example, if they choose to test paper towel absorbency, they need to make sure the two paper towels are the same size. Also discuss the need for multiple trials to get accurate data.
You have a few options for students to submit their work:
Inevitably you will have students that changed more than one variable, didn't have a control, made measuring errors, etc. You can always give them feedback and request the repeat the experiment with needed improvements. This is a great learning opportunity for them, and they will understand that the nature of science is to always go back to the drawing board and improve on prior experiments.
Have any other consumer science labs you love to do with students? Leave them in the comments and I'll add them to the list!
WHAT IS CITIZEN SCIENCE?
Citizen science is when the public participates in scientific research. Every-day citizens share and contribute data with the goal of increasing scientific knowledge. You do not have to be a trained scientist in order to participate.
WHY YOU SHOULD TRY IT
Citizen science is great to do with students because:
Ready to try it out? Here is a list of websites and project ideas to get you started.
1. CitizenScience.gov is a government website that has a TON of project ideas and is a great place to start. You can collect data that will be used by NOAA, USGS, National Science Foundation, and even NASA.
2. The Great Backyard Bird Count is a website run by the Audubon that encourages students to get outside and start birding. They are looking for regional data where people can upload pictures and species of birds they see in their neighborhoods. Time to dust off those binoculars!
3. National Geographic has a list of citizen science projects, ranging from wildlife observation, measuring night sky brightness (light pollution), butterfly census, listening for frog and toad calls, and more.
4. SciStarter.org is a website put together by Arizona State University and the National Science Foundation. You can search for projects near you or online only.
5. Project Green Challenge is a website that gives students environmentally-themed challenges. You can register your school and enter to win prizes!
6. Zooniverse is "people powered research." This website has a ton of ongoing projects that also venture into other content areas outside of the natural sciences.
7. inaturalist Do you ever take pictures of insects and cool species in your yard or neighborhood? inaturalist is a website (and phone app) that allows you to upload pictures of your findings and share/discuss with fellow naturalists.
8. Captain Planet Project Hero is a PBL driven website where students can help threatened species and ecosystems in their area.
9. The GLOBE Program is looking for people to contribute data for cloud types, mosquito habitats, and land cover observations.
10. Project Budburst was created by Chicago Botanical Garden. Their goal is to uncover the stories of plants and animals affected by human impacts on the environment.
11. Gorongosa Webcams If you've ever used curriculum from Biointeractive, you know it's pretty stellar. In this lesson students study webcams from Gorongosa National Park in Mozambique and do animal identification.
12. Pollinator Live is a website that includes links to a bunch of citizen science projects centered around attracting and monitoring pollinators in your area. Teach students the importance of pollinators!
Looking for low stress and low prep ideas as we navigate distance learning? Here are 5 ideas you can use with your secondary science students:
1. CLICK HERE to check out virtual field trips your students can explore!
2. CLICK HERE to see a full list of science related movies, TV shows, and documentaries.
3. Check out American Chemical Society's blog post on kitchen chemistry ideas!
4. Have students create a photo journal!
5. Have students build something out of recycled materials. Ideas could include a rube goldberg contraption, a parachute, or a solar cooker.
Hope those tips help you through this tough time!
It can be frustrating when students are absent on lab days. You spend a lot of time setting up and often spend money out of your own pocket for supplies. If you are doing labs often or teach multiple preps, dealing with student absences just gets harder to juggle. By the time the student comes back and asks "what did I miss?" I've often torn down the lab or passed the supplies onto another teacher in my department and don't have them available. Instead of scrambling to re-set up the lab every time, here are a few alternative options:
1. DO THE LAB MAKE-UP ON THEIR OWN TIME
If the lab isn't super labor intensive and students can read through the procedures on their own to figure out what to do, I have them come in and make up the lab on their own time. Luckily my school has an advisory period built into the school day where students can travel to get caught up on their classes. If you don't have this luxury, they could come in during lunch or after school.
2. SUBSTITUTE THE WET LAB FOR A VIRTUAL LAB
There are a bunch of virtual labs out on the internet that you could substitute for the wet lab. Phet or Glencoe are great options to check out.
3. COPY THE LAB DATA FROM A PEER AND ANSWER THE ANALYSIS QUESTIONS
This option is my go-to for labs that take multiple days. If students missed the first day of experimental design or data collection, they can come back in, join a lab group, and finish the lab. If it was a one day lab, you can have a "master copy" of data that absent students can copy down and analyze before answering the post lab analysis questions.
4. DO AN ALTERNATIVE ASSIGNMENT ON THE SAME TOPIC
If you can't find a virtual lab on the same topic, try and find an article or worksheet on the same topic and use that assignment to replace the lab grade. Newsela is a great place to find free non-fiction articles. Don't forget to look for freebies on TpT! (type in the topic you are looking for and filter by grade and cost).
5. EXCUSE THE ASSIGNMENT
I would like to begin with a disclaimer that this is NOT something I do regularly. I think students need to somehow show proficiency on a standard, not just get it excused. However, if a student tells you they were absent for a week because they were in the hospital or had a true family emergency that you can verify, sometimes they just need to be cut a break. Realize they will have missing assignments from 6 other classes on top of yours, pick which assignments you think are vital for mastering the standard, and excuse the rest.
The moral of the story: Don't lose your sanity trying to have every absent student do make up labs.
I posted on Instagram last week pictures of preparing agar for my go-to first week of school lab: testing the 5 second rule. It’s a great lab for back to school because students are super engaged and it’s a good way to review variables and how to set up a controlled experiment. I had a bunch of people ask questions about how I prepared the agar and set up the lab, so here is a blog post to answer all your questions!
WHAT MATERIALS WILL I NEED?
-Sterile petri dishes
-Dehydrated nutrient agar
-Hot plate with stir capabilities
-Heat resistant gloves
-Optional: Autoclave and incubator
DO THEY NEED TO BE STERILE? DO I NEED AN AUTOCLAVE?
If you want to have accurate data, yes, your petri dishes need to be sterile.
Each year, I open a new sleeve of plastic petri dishes so I can assure they are sterile. If you don’t have access to new ones you can re-use petri dishes, but make sure to either sterilize them in an autoclave or clean them thoroughly in a bleach solution followed by a distilled water rinse.
HOW DO I MAKE AGAR PLATES?
Methods will vary slightly depending on the agar you ordered, (directions should come with your nutrient agar, or should be available online from the vendor) but here is the general process:
1. Measure out the desired amount of nutrient agar and distilled water and pour into a clean beaker. For the agar I order, the recipe calls for 23g of dehydrated agar per 1 liter of distilled water. (Note: 1 liter of agar will fill roughly 30 - 40 petri dishes).
2. Add a stir magnet to the beaker and place on your hot plate. Turn on both the heat and the stir settings.
3. Continue to heat and stir your agar until it is boiling. This may take a while, but be patient- if you don’t wait for it to boil, your agar won’t solidify once it cools.
4. If you don’t have access to a hot plate, you can use the microwave. Place beaker and agar mixture into the microwave and heat for 3 minutes. Continue heating in 1 minute bursts until the agar is completely dissolved and the mixture begins to boil.
5. As you are waiting for the agar to boil, lay out your sterile petri dishes on a heat resistant counter. Keep the lids on as much as possible to avoid any contamination.
6. Once agar has come to a boil, remove from heat using heat resistant gloves. Lift the lid on a petri dish, carefully pour agar into the petri dish until it is roughly 2/3 of the way full, and promptly return the lid. Continue until all your agar has been used.
7. Allow the agar to solidify at room temperature- this shouldn’t take more than 15 minutes.
8. Once the agar has solidified and cooled, store them upside down in the fridge until you are ready to use them. Storing them upside down will ensure that any condensation drips onto the lid, not onto your agar.
HOW MANY DAYS BEFORE USE CAN I POUR THE PLATES?
I typically pour the petri dishes a day or two before I need them and store them in the fridge. Petri dishes in the fridge will be good for a few weeks before they begin to dry out, but the sooner you use them the better.
I HAVE 150 STUDENTS. HOW MANY PLATES WILL I NEED TO PREPARE?
It can be pricey to pour a ton of plates every year and with 150 students it would be way too expensive (and a lot of work!) to pour every student their own plate.
When I do this lab with my students, I put them in groups of 4. With roughly 32 students per class, I pour 8 plates per class. As a lab group I let them choose a variable to test and have them whiteboard their experimental design. Some groups want to change the amount of time the food is on the floor, other groups want to test different food types, and other groups want to try out different dirty surfaces. Once I’ve approved their design (to make sure they have a control) they can begin the lab.
DO I NEED AN INCUBATOR?
Okay, so your students set up the lab, but do you need to leave them in an incubator?
If you want quick results (overnight) then an incubator will speed up the process. But if you don’t have access to one, just let the plates sit for an extra day or two in your room temperature classroom and you will still get plenty of bacteria growth. Again, leave them upside down (agar side up) so you don’t have issues with condensation dripping into your agar.
HOW TO STUDENTS COLLECT DATA?
Since I do this lab the first week of school, this is an excellent time to review the difference between quantitative and qualitative data. Once students get their plates back, I have them make both qualitative observations and measure quantitative data.
You can have students collect quantitative data by counting colonies, but a much easier way is to use a grid and calculate percent coverage. You can purchase gridded stickers that stick onto your petri dish lids, or just do it yourself with a fine point sharpie marker. All students have to do is count the number of squares that have bacterial growth, divide it by the total number of squares, and multiply it by 100 to turn it into a percentage.
HOW DO I DISPOSE OF THE PLATES?
It is important you do not place your plates in the trash without first taking some precautions. While bacteria in small numbers may be harmless, once cultured into millions of cells they can pose a greater threat. There are a few ways to properly dispose of your used agar plates, depending on what you have available:
1. If you have an autoclave, you can autoclave your plates per the directions on your autoclave (generally at least 30 minutes).
2. If you used glass petri dishes and don’t have an autoclave, prepare a 20% bleach solution and spray your plates down. Allow the bleach to soak into the agar for 1 hour before placing agar in the trash. Then thoroughly clean your empty petri dishes again with a bleach solution and distilled water rinse.
3. If you used plastic petri dishes that you can afford to part with, you can place them in bio-hazard bags and have your district arrange for bio-hazard pick up. It doesn’t hurt to spray them down with a 20% bleach solution before placing them in bio-hazard bags.
I hope that answers all your questions! If you are interested in the lab handout I use with students to test the 5 second rule, you can find it HERE!
One of my favorite parts of the cell unit is teaching about membranes. If you ask me, they are by far the most important part of the cell. Everything the cell does is because it is responding to signals received by the membrane. While many students think the nucleus is in charge, it is in fact the membrane that is directing cell processes. (You can read a blog post about why the cell membrane is more of the control center than the nucleus by clicking HERE).
There are a ton of lab options you can do for students to understand the structure and properties of the cell membrane. Check out these 10 resources you can implement in your classroom:
MEMBRANE PROPERTIES & STRUCTURE
1. Visualizing the Membrane: Using analogies really helps students visualize the cell membrane in their head. I read this analogy a few years ago in a book by Dr. Bruce Lipton and have been using it ever since. I tell the students the cell membrane is like a bread and butter sandwich. If I poured water on top of the sandwich, what would happen? Students can recognize that the water would only soak through the bread and stop at the butter layer. Since students already learned about lipids being hydrophobic from our macromolecule unit we circle back to that discussion. Click here if you would like to check out a worksheet that goes with this analogy.
2. Bubble Lab: Who doesn't love to play with bubbles?! Bubbles are a fun way to examine properties of membranes because they are similarly made of molecules that have a hydrophobic side and a hydrophilic side. In this lab students learn how membranes are flexible, can self repair, how materials move in and out, and more. Materials are inexpensive and the fun is endless. You can find it FREE HERE.
3. Interactive Website: Check out this website that walks students through the structure of the cell membrane. This website is great for high school students. I like that it shows the actual molecular structure instead of just head and tail blobs... this allows students to really comprehend the structure. While you are there check out some of his other interactives- they are all great!
MEMBRANE TRANSPORT (Many of these labs demonstrate the same concepts. Pick one or two that you like!)
4. Carrot lab: This lab is great for middle school students to understand osmosis. In this activity, students will soak a baby carrot in fresh water and salt water overnight and observe any changes to it's physical appearance and mass. (You can use celery, potatoes, or any other vegetables you have on hand). I prefer using vegetables over gummy bears (Which is a teacher favorite) because vegetables are actually made out of cells.
5. Egg Lab: In this classic lab, students dissolve an egg shell with vinegar and are able to observe a "naked" egg. Once the shell is dissolved you can soak the eggs in different liquids such as distilled water or corn syrup and observe the effects on the egg size and mass. This lab is fun, but I don't do it every year because there are always messy casualties. You can read more specific directions HERE.
6. Dialysis tube lab: In this ADI lab, students need to design an experiment to determine the effect of solute concentration on the rate of osmosis. (Note: ADI labs are available for free online, but the hard copy books must be purchased if you want the answer key). This is a great lab for high school students who are ready to think critically and design their own experiment. Sugar can also be used instead of salt. When I had students complete this experiment I pre-mixed the solute concentrations and we discussed how dialysis tubing works but had students figure out their own experimental set up.
7. Onion Skin Lab: Have you already taught students how to use microscopes? If so, this lab is fool-proof. In this lab, students observe a thin layer of purple onion under the microscope. They make wet mounts with fresh water and salt water, and observe what happens to cells placed in a hypertonic environment. You can read a blog post with some tips HERE. It's great because it's easy (no dye needed) and really inexpensive.
8. Osmosis Tonicity Worksheet: I created this quick 2 page worksheet to use as a formative assessment before I tested students on osmosis. It includes a handful of scenarios and students have to identify how the cells will respond and if the solution is hypertonic, hypotonic, or isotonic. You can download it here.
9. Amoeba sisters: Do you want to enrich your lesson with some videos? Amoeba sisters videos on youtube are great for review and reinforcement. There are two video clips that cover topics relating to the cell membrane, one titled "Inside the cell membrane" and another titled "Cell Transport."
Don't forget that many of the amoeba sisters videos have worksheets to accompany the lesson. They can be found here.
10. Cell membrane close reading: One thing students tend to struggle with is understanding how the cell receives and responds to signals. When we use the term "environment" students think about the outdoors... but the environment for a cell is the conditions inside our bodies. I wrote this close reading article to help students understand how the cell receives and responds to signals, and how genes can be turned on and off. It is a great segue into genetics because it introduces the topic of epigenetics.
I hope you have a great cells unit and your students have a blast with some of these labs!
Getting out the microscopes is one of the best parts of teaching biology. I love hearing the ooh's and aah's when they finally get the specimen into focus. But if you've taught biology before you know it can also be one of the most exhausting units- constantly running around the room because "Mrs, I just don't see anything!" or they end up drawing dust, air bubbles, or their eyelashes. After a decade of tweaking my microscope unit, I've come up with some tips to help save your sanity.
1. Don't get them out until it makes sense.
While it may be tempting to get microscopes out the first week of school, it just doesn't make sense. If you aren't going to use them regularly until later in the year, why are you teaching them the names of the microscope parts in week 1? They will forget the information and you will find yourself reteaching. Hold off until you get to cells (or whichever unit you need them regularly).
2. Make sure they know the names of all the microscope parts.
It can be really frustrating when you are trying to help a student, tell them to adjust the fine focus, and they look at you like you are speaking another language. Because of this I don't let students start using the microscope until they can tell me the names of all the parts. We take notes on it and I give them a short quiz at the beginning of the unit. If you want to check out the worksheets I use for teaching parts of the microscope, click here.
3. Try a virtual lab first
Virtual labs are a way to provide students extra practice on the methods of using a microscope before getting out the real deal. Extra practice never hurts, especially for your SPED or ELL students who would really benefit from some visual practice. Check out this site from University of Delaware.
4. If your scopes have a single ocular, teach them which eye to use.
The microscopes in my room have a single ocular lens, so students often ask me which eye to use. This video shows an easy and quick way to teach them which of their eyes is dominant.
5. Start with prepared slides.
I always begin with prepared slides. I put 4 different prepared slides at each lab group, and have students practice focusing and drawing. The first day of prepared slides you will hear a lot of "I don't see anything!" but eventually they get the hang of it. Not all of your students are going to be great artists, but I make sure they know when they turn in their drawings they must a) be drawn to scale, and b) be neat. No scribbles allowed. I should be able to look at the drawing and easily tell what slide it is. I use these lab templates for prepared slides. Don't have access to prepared slides? You can make your own! Check out this blog post on how to easily make a classroom set.
6. Encourage peer help
There is only 1 of you and 30 students. It is physically impossible for you to be running around helping every single student. One day when I was about to rip my hair out I made this poster and hung it up on the whiteboard. Students were not able to call me over for help unless they had checked all of these items off the list. Most of the time their neighbor can help them resolve the issue before you need to be called over. If they still needed help after going down the checklist, then they could call me over. It has helped greatly! You can download this for free in my TpT store here.
7. After they have mastered prepared slides, then move on to wet mounts
Wet mounts can be much more exciting than prepared slides because you can have students look at their own cells (if your school allows you to do a cheek cell swab) or watch microorganisms swimming around. Protists are an absolute blast to watch, but students need to have mastered focusing the microscope and scanning relatively quickly in order to see the protozoa zooming around. You don't have to spend money ordering protists from a supply company, you can easily get your own culture going. Check out this blog post on how to set up a hay infusion. During this lab, I allow students to take pictures or videos with their phones. It takes a steady hand, but they can line up their smart phones with the ocular and get a decent video.
It can be really frustrating when the bell is about to ring and students try to walk out of the classroom without cleaning up. General microscope clean up procedures should include:
a) Removing your slide and returning it to where the teacher directs
b) Turn the objective to low power
c) Turning off the light
d) Putting the dust cover back on
e) If you are putting microscopes away for the day, unplugging and winding the cord around the arm.
I have this poster hanging on my microscope cabinet- it is a freebie from my friend Bethany Lau. You can find it in her TpT store.
Don't have a class set of microscopes? Check out some alternative options.
I hope these tips help your microscope unit run more smoothly! Have fun!
Why are cells so small? And why are we made of so many? It seems like it would be easier to be made of 100 or even 1,000 cells instead of trillions. One of the reasons we teach students that cells are small is because they need a large surface area to volume ratio. The larger the ratio, the more efficient the cell is at moving materials in and out of the cell.
I've seen cell size labs that use different sized agar cubes prepared with a pH indicator. The cubes start pink and lose their color as they soak. (Here is a free version from Flinn if you are feeling ambitious!) Frankly with 3 preps a day this year, I didn't have the time or energy to pour agar cubes. Instead I found a quick and easy way for students to see the same concept- using beets and bleach.
In this experiment, cut different sized beet cubes, a small, a medium, and a large. The students soak the cubes in bleach for roughly 30 minutes (I had them doing some practice SA:V calculations while they waited). Tip: if you use tupperware containers with lids you won't have to smell bleach fumes all day, or you can put parafilm over the beakers.
After 30 minutes of soaking, students remove the beets, cut them open, and measure the amount of red pigment remaining. It is an easy way to see that small cells are more efficient at moving materials in and out. If you are interested in seeing the lab write-up I wrote, you can view it here.
I hope your students enjoy it!