8 Demos for Biology

Are you looking for ways to hook your student’s attention in the upcoming year? This might be a challenge if your school is starting the year virtual or hybrid and if you are accustomed to using hands-on and group activities to engage your students. Since we can’t let students work together, I’ve put together a list of biology demonstrations you could do in front of a group of students in a classroom or during a virtual class given over the Internet. It might not be as fun as letting students experience the process themselves, but I think demonstrations give great visuals that hook students into the lessons and help consolidate hard concepts. Here are 8 demos that you can use in a biology or life science class.

  1. Water Demos

There are so many cool demonstrations you can do to show different properties of water! You can use pennies and a water dropper to show surface tension, string and colored water to show adhesion, (see this video), and colored water and paper towel to show capillary action just to name a few. I think all of these would translate well to a virtual class session on Zoom or Google hangouts or you might  even be able to have students do some of these activities in class if you have enough materials for each student. Or better yet, make it a challenge for students to try the adhesion activity with string and colored water at home. Have them document how it went by taking pictures or making a video and explain what is happening. Or challenge students to find examples of cohesion, adhesion, and capillary action around them homes and take pictures of what they find. This is a great way to get them away from the computer for a little while!

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One of my students demonstrates capillary action using paper towel and color water. 
  1. Testing for Macromolecules

Rebecca over at It’s Not Rocket Science has a great lab for testing for macromolecules and when I taught biology I looked forward to doing it every year! Unfortunately, students won’t be able to do this groups like normal, but I still think you could do this as a demo in front of students if you are in the classroom next year. Becca’s lab sets up a scenario in which there is a murder victim and students must investigate the contents of the victims stomach to figure out where they had their last meal and who murdered them. I think if you played this up a lot, the demo could be just as exciting as a lab they do themselves. However, if you are teaching virtually next year, this is trickier. You could easily test for starches and fats using iodine and a brown paper bag, but most of us don’t have Benedict’s or Biuret’s solution at home to test for proteins and simple sugars. My suggestion would be to use a standard lab and start the demonstration with your class during a virtual session and show them how iodine can test complex sugars and a brown paper bag can test for fats. Then students could watch YouTube videos on their own to see how we can test for proteins and simple sugars. (I think this video and this video walk through the steps very nicely) Not quite as fun as doing it class, but students should get the picture or how different foods contain different macromolecules.

  1. Cell Size

Becca, who writes the blog Science Lessons That Rock, has a great lab for demonstrating the importance of cells size that uses beets and bleach. I have not tried this lab with students, but I’ve always wanted to! The set up looks pretty easy and it looks like you could do this in class or virtually. (Becca also has lots of other great resources for teaching cells so check out her blog!)

  1. Osmosis

When I taught biology, students often had difficulty learning about cell transport and I found that visuals and labs really helped. There are many well known labs for teaching osmosis that use eggs, gummy bears, cucumbers, potatoes, or raisins. Personally if I was doing this as a demo for my students in class or online, I would probably do the raisin lab with sugar water (something like this). I’d set it up 24 hrs. in advance and show students the difference between the raisins hypotonic and hypertonic solution. If you don’t have access to a food scale, I think the visual of the swollen raisins vs the wrinkled raisins still works. Make sure to follow up your demonstration with a discussion or visual about WHY the water moves into or out of the raisin depending on the solution they are in.

  1. Fermentation

I always loved doing fermentation labs with my students when I taught biology. I especially loved how my room smelled! A lab like this, could easily be turned into a demonstration. The materials are easy to find around the house (as long as we don’t have another yeast shortage!) and it’s fairly simple to set up. However, I know that some teachers have difficulty getting the yeast to respirate if they don’t have a warm spot to put the bottles. If you are at doing this home for a virtual class, you might be able to preheat your oven and set the bottles on top of your warm stove (just like you are actually making bread) and that should help the yeast do their thing. If you are at school, a warm water bath might work too. I also used to do a project where students had to make something with yeast at home, take pictures of the process, and answer a couple questions. You could have students do this on their own and then have a bread eating party during your next virtual class time.

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An example of how my students tested the affect of yeast on sugar. We were able to place these on a heater in my classroom to get the yeast to respirate.
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Delicious treats made with yeast made by my students!

 

  1. Respiration

When I taught Biology, I usually did a lab in which students tested the effect of exercise on cell respiration using bromothymol blue. You can find a lot of free labs for this online and I think this could work as a demo or could be done virtually. You can find a demo of this lab here. If I was in front of a group of students I might explain the set up to my students have them do some research about bromothymol blue and have them make a prediction about what would happen when I blew air into the bromothymol solution. If I was doing this virtually, I might even have students time how long it takes for the solution to turn color when I’m resting, then jog in place for a minute (if you feel comfortable and able doing this over a Zoom class), then have them time how long it takes for the solution to turn color after exercise. You might have to buy some bromothymol blue if you are doing this at home, but it isn’t very expensive.

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One of my students turns a bromothymol blue solution green using carbon dioxide from their breath. 
  1. Photosynthesis

Along with cell respiration, photosynthesis can be a really hard concept for students to grasp and labs involving photosynthesis can sometimes be tricky. I’ve done labs with Elodea plants with varying success and I know labs that involve the leaf discs can be frustrating for students when they can’t get them to sink. This lab might work as a demonstration and I’ve greater success with this lab than others. It involves putting Elodea into a carbon dioxide and water solution and watching the bubbles produced when it is placed in a dark place vs. when it is placed in a lighter place. I think you could do this as a demo at school or at home and show students the results over a virtual class session. The materials are things you can easily get at a grocery and pet store. If you don’t have a bright lap to use, you could set up two jars and place one in a sunny window and one in a dark closet. Take the jars out right before class, and your students should be able to see that the plant placed in a sunny place is producing more bubbles thus undergoing photosynthesis at a faster rate.

  1. Strawberry DNA

This classic strawberry DNA lab can easily be set up at home for a virtual or done in front of students. The visual of the DNA is something that always interested my students when I taught biology. This can be used to teach about DNA, but also polarity, cell membranes, and density.

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This lab that extracts the DNA from a strawberry could be used as a demonstration in front of class instead of doing it as a lab. 

This year is going to look so different from every other school year and I know that stress levels are running high as we plan for what is ahead. That being said, you don’t NEED to do labor intensive demonstrations if it seems like it’s going to stress you out. I know that some of these activities require a lot of materials and need to be set up ahead of time and if you don’t have the time or the space, then don’t feel pressure to do demonstrations! Or just pick one or two really simple demos and commit to those. If there was ever a year to focus on making teaching simple, this is the year!

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Anyway, I hope these are helpful and that you find something that will work in your classroom. 🙂

Take Care!

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10 Demos for Anatomy

Well, it’s mid-July and we are slowly starting to get a picture of what our schools might look like next year, but there is so much uncertainty around what teaching will actually be like. I think one thing we can plan on for sure is that we won’t be able to lab and group activities the way we normally do. With the threat of Covid still so prevalent, I imagine that we won’t be able to put students into small groups in close proximity to each other to work on a lab. Which is so sad! I always think labs are best parts of science class, but we will have find to some other ways to engage our students in our content. One way I think we can do this is by using demonstrations frequently whether it’s in front of a group of students or whether it is done virtually over a Zoom or Google Hangout session. Demonstrations are done by the teacher while students watch and make observations and can be used to show a process, illustrate a concept, or be an analogy for a difficult concept. Demonstrations done in real time in front of students can help draw their attention and give them greater clarity about difficult topics.

I’ve been brainstorming and made a list some demos I will probably be using in my anatomy classes next year. Some are demos I’ve done before and some are labs that I just won’t be able to have students do. Also, while some are high school specific, others would work just as well in a middle school class learning about body systems.

  1. Rubber Band Chicken Bone

You might be familiar with this experiment where you put a chicken bone (from a rotisserie chicken for example) into a jar of vinegar for 5 days or so and the vinegar reacts with the calcium in the bone dissolving it and leaving behind a bendy bone made of collagen. Instead of doing this as a lab with students in groups, you could easily set this up ahead of time and show it to the whole class as a demo in person or over zoom. You could use this as a simple way to illustrate the importance of calcium in bones but you could also make it more inquiry-based with older students. You could show them the bendy bone and then have students hypothesize about what happened and what is left behind in the bone before they do research to discover what actually happened.

  1. Twizzler Muscle Model

Muscles are pretty complex organs and my students usually have some trouble understanding the structure of muscles and how they work to contract and relax. I think this Twizzler model activity to be a helpful model for how muscles are bundles of bundles of different fibers that work together. I normally have students do this as a group activity with Twizzlers, but I still think this activity would be valuable as a demonstration in-person or virtually followed by a class discussion. I envision doing this in front of my students and having them identify each bundle and the layer of connective tissue around it as I work to put the bundles together to make a completed muscle. The most difficult part of this is that you probably won’t be able to let students eat the extra Twizzlers you have! 😦

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  1. Chicken Wing Dissection

A chicken wing dissection is a versatile lab that you could use in high school or middle school and I think you could still use this as a demo, although I’m not sure if it would translate well virtually (if you or your students don’t have a great Internet connection it could be difficult to see all the structures). I think that dissecting a chicken wing (here is an example of I have my students do) is great for showing the difference between tendons and ligaments and you can pull on the different muscles of the chicken and show students how muscles pull on bones to create movement. I also got comments from students last year saying they never thought about meat as being muscle which is a good lesson too. Again, I’m not sure how well this would translate as a demonstration over the Internet, but chicken wings are pretty easy to get, so maybe you could have students do this on their own at home and document what they learned.

  1. Blood Types

I love this demonstration and its so helpful in showing students which blood types can be donated and excepted by other types! All you need are clear cups, water, and some food coloring. You can read about this demonstration here. You might also want to discuss what ACTUALLY happens when blood types mix (agglutination) so they have an idea of why it’s dangerous to mix blood types.

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  1. Reflexes

I normally like to have students test each other’s reflexes but I don’t think that will possible next year. I usually have them test the patellar, bicep, tricep, and the Babinski reflexes. However, I think you might be able to do this as a demo in front of the whole class. If you are in school, you could maybe demonstrate these on a colleague? I’m not sure. You could also demonstrate these virtually to students by testing them on a spouse or roommate. Of course, you can always show YouTube videos of these reflex tests, but it might be more fun for students to see you actually demonstrate on a real person. Also, if you don’t have a reflex hammer laying around, you can make one out of popsicle sticks, rubber bands, and a rubber eraser and it works pretty well.

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  1. Digestive System Model with String

You can find plenty of activities online for modeling the length of the digestive system. You could show the  actual length of the digestive system or one that models it with string to a smaller scale. I had students do this individually last year during online teaching (the did an assignment like this one from Biology Corner), but you could also demonstrate it front of a classroom and maybe also online during a virtual lesson.

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  1. Digestive Enzyme Demo

I wrote about this in a previous blog post, but this a great demo that you can easily do in front of a group of students or virtually. I used gelatin, pineapple, cornstarch, iodine, oil, and soap to demonstrate the digestion of sugars, protein, and fats. It’s a great way to reinforce that there are specific enzymes for specific nutrients and that they get digested in different areas of the digestive system.

  1. Egg in a Jar

This a simple and powerful demonstration of the important of cerebrospinal fluid around the brain and impact of traumatic brain injuries. All you need is an egg in a jar of water and you will find that when you shake the jar, the egg can break when if it hits the side of the jar. It’s a good example of how helmets in sports only go so far in protecting the brain. I also like to show this video of a real brain that shows students how soft and vulnerable the brain is. (Disclaimer: this video is might not be appropriate for all students. I only show it to high schoolers.)

  1. Lung Model

My school has one of these lung models where there are balloons inside a large container and you can pull down on a rubber diaphragm to make the balloons inflate and deflate like the lungs. The way that pressure changes inside the thoracic cavity allowing air to enter and leave the lungs can be really confusing for students so I like to have a good visual, but if I had to teach from home, I wouldn’t have this model so I suppose I could make one out of a plastic bottle and balloons and show students over a Zoom session how inhalation and exhalation work. I also think this model could work too. It uses balloons, straws, and a glass of colored water and is supposed to be a model of how the heart beats. However, because the increased air pressure is pushing the water of the straw, I think it could work to demonstrate exhalation.

  1. Blood Model

I loved doing this model with middle school students, but I think it could work as a demo in a high school class too. I have used cheerios, navy beans, lentils, and water to represent the different parts of blood but there are a variety of things you can use. I would make sure the emphasize the different amounts of each of these components. Make sure students understand that blood is mostly plasma followed by red blood cells, white blood cells, and platelets.

If you are a science teacher, I hope you find this helpful and that some of these will work for your classroom. I would love to hear if you have any other demonstrations you plan on doing in an anatomy or human body systems class or any other ways you plan on adapting your class for the upcoming year!

Take Care!

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Seven New Things I Did In The 2019-2020 School Year!

Oh, 2019-2020. This school year has been a year full a changes for me, as I’m sure it has been for you as well. As of this writing, we have finished up a school year that concluded with pretty much every school in America trying to do online or at-home learning due to the coronavirus pandemic and we are currently staring down an upcoming school year full of uncertainty.

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For me, I also started teaching at a new school in August 2019 after teaching at my previous school for 5 years so the whole year kind of felt like a giant upheaval. With so much change, I got the opportunity to try some things in the classroom and was forced to do new things with online teaching in the spring as I’m sure you did too! So after some reflection, I want to focus on some of the successful and fun new things I did with students this year. So I give you my top 7 new things I did this year with success. (For reference I mostly taught high school anatomy this year so some of these activities are specific to an anatomy class, but some of these ideas can work in a middle school science classroom or in a classroom of any subject area.)

Also, some of things mentioned below might not be applicable to the classroom next year if we are teaching online or if we are not allowed to do labs in groups, but some are things that can work online or in a socially distanced classroom. I hope you find something here you can use in your classroom!

 

  1. Rat Dissection

For the first time this year I taught anatomy with another teacher and got to see some different ways to do things in the anatomy classroom. One of things I was most taken aback by was that my new co-teacher typically does a rat dissection in the beginning of the year in addition to a pig dissection in the spring at the end of the year. At first I found this very interesting, but after I completed it with my class I realized that it was genius! A full dissection right at the beginning of the year is a great was to introduce all the body systems all at once, it forces students to use the anatomical terms and directions they have been learning from the get go, and it gets students EXCITED. The first unit of anatomy can be intimidating to students (it’s full of terms they have never heard of) but I think the dissection helped hook them in even though the first impressions of the class can be overwhelming. It was also nice to be to refer back to the dissection throughout the year. (“Do you remember the spleen during the rat dissection? It was that really dark red organ on the right side toward the back of the rat?”) I realize that two full dissections can be costly, but if your school can afford it or if you have a small anatomy class, a big dissection at the beginning of the year can be really helpful and meaningful for students. I have been buying dissection specimens from a company called Biology Products for a couple years and I like their specimens. They do use formalin in their preservation fluid, if that bothers you, but I find it worth it for the price.

  1. Chicken Wing Dissection

Another new dissection I did this year was the chicken wing dissection during our muscle unit and this is so simple and straight forward, I don’t know why I haven’t done it sooner. Chicken wings can be purchased pretty cheap and it’s a nice way to help students tie together the skeletal and muscular systems. Something I want to work going forward with anatomy is better showing how body systems work together and that they don’t just work in silos sperate from each other. Also this lab can be simplified for middle school or made more complex for high school. So versatile! You can find lots of different versions of this lab by just Googling “chicken wing dissection lab”.

  1. Spirometer Lab

Testing for lung volume was a new lab I did during our respiratory unit and I tried it two different ways with different classes. With my lower level students I used this lab from Biology Corner using a balloon to get a rough estimate of lung capacity. With my upper level students I use a lab from my co-teacher (similar to this one) that used lung volume bags. Of the two labs, I think the lung volume bags worked a lot better and students got a kick out of seeing their estimated lung volumes. Obviously, I don’t know if we will be able to do this lab next year with the threat of the corona virus still eminent, but this lab was fun for students and I will do it again when it is safe to do so. The lung volume bags and parts are pretty simple and not too expensive. Also I think the lung volume lab from Biology Corner could work in a math class learning to calculate the volume of a sphere.

  1. Digital Escape Room

I have done one escape room that I made myself a couple years ago with some success but this May, as my students losing interest in online learning, I purchased this premade digital escape room for my students to change things up a little. It was a slightly different way for students to review what they had learned and they seemed to enjoy it. It worked well over Zoom (I put students into breakout rooms and emailed them the different levels as they worked through each one) and it I think it was a nice way for students to not only to see what they knew and didn’t but it gave them a little time to interact with each other in small groups as well. Over the summer I plan on trying to make my own digital escape rooms for a couple units. I much prefer doing escape rooms manually with locks or puzzles they do together in person, but I think the digital escape rooms with be great with the adjustments we will have to make next year with COVID-19.

  1. Digestion Demo

Since we couldn’t do a lab during our digestion unit this year, I did a demonstration over zoom that showed the digestion of carbohydrates, proteins, and lipids. I had students fill out a handout during the Zoom where they simply listed what they observed and what they thought was happening. After the demonstrations we discussed how each molecule was digested and how it connected to what happens in the digestive system. This seems to work really well as it gave students a visually of digestion even if it was over Zoom and not in-person. I plan on making a list of other demos that will fit in and help students understand concepts in anatomy for next year since I’m not sure if we’ll be in the classroom again or if we will be able to labs in groups like we usually do.

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You can use pineapple (which contains an enzyme called bromelain) to show how enzymes digest protein, like the collagen in gelatin.
  1. Podcasts

During online learning in the spring I was looking for ways to keep things fresh and interesting as I felt like students were losing motivation and interest in school as it became more clear that we would probably not be returning to in person classes at all in 2020. Giving students a podcast to listen to and some simple questions to answer seemed to interest my students and I think it is a great way to help students learn new material and practice listening skills. It’s also a way for students to hear from experts in the field and they hear stories that might new otherwise get from reading an article or textbook on the subject. It’s also just a nice way to change things up a bit if students have been doing a lot of reading or watching videos for your class. This year I had students listen to podcasts about the Tuskegee Syphilis study, the coronavirus, and (my personal favorite) a short one about giardia. There are loads of good podcasts you could use in literally any class!

  1. Retrieval Practice

Last summer I read two books: Small Teaching by James Lang and Understanding How We Learn: A Visual Guide by Weinstein, Sumeracki, and Caviglioli and both books emphasized the evidence (such as this) that supports the use of retrieval practice in the classroom. Retrieval practice is simply having students try to pull information they have learned from their memory to help solidify new information. This strategy is backed up by multiple studies so I made a point to use it more in my classroom and I think it made a HUGE difference in student learning. Anatomy has a reputation for being all about memorization and memorizing is a big part of the class. Memorizing the meaning of so many new words is the first step for students who are interested in the medical field or just learning more about their bodies and it sets them up for being about to think critically about problems that can occur in body systems. I think the various activities I did using retrieval practice helped students retain all the new information they were learning, helped them do better on their assessments, and help them gain confidence in the class. You can read more about retrieval practice here and this blog has some great and simple ways to implement this in your classes if you are interested.

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For this exercise in retrieval practice, I had students list the levels of organization in the human body from memory (they did this in green pen). Then they looked at their textbook and consulted with each other and fixed any mistakes they made (they made corrections in the brown pen). Afterwards we reviewed this together as a class. This is a great way for students to practice pulling information from their memories and for them to assess what they do and do not know.

I also want to mention that there is a list in my head of 10-20 new things I tried this year that were not successful or did not work well enough to mention in this list. There is also a list of old things I have done in years past that did work at all at my new school or with my new group of students or that didn’t translate well to online learning. Trying something new and having that lessons fail in front of students is always uncomfortable but I always feel like it’s better to try new things and fail than to not try at all. The global pandemic has made teaching less than optimal right now, but it’s also an opportunity to try and fail and succeed with new lessons, activities, and approaches.

What new things have you been trying out or hope to try out next year??? I would love hear about it in the comments!

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